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A Churg

Publications and source records attributed to A Churg.

At least 127 records · Page 7Linked to original sources
PubMed1987

Pulmonary veno-occlusive disease following therapy for malignant neoplasms.

We report three cases of pulmonary veno-occlusive disease which developed following treatment for malignant neoplasms. Two patients received single agent BCNU chemotherapy for malignant gliomas. The third patient underwent combination radiation and chemotherapy for Hodgkin's disease. Isolated case reports of pulmonary veno-occlusive disease following therapy for malignant disease are reviewed and clinical features summarized. Pulmonary veno-occlusive disease in this setting is thought to be rare. However, the diagnosis is rarely suspected clinically and is difficult to diagnose pathologically. Therefore, the true incidence of this complication is unknown and may be higher than believed. It is important that both clinician and pathologist be aware of this entity; otherwise, elastic tissue stains may not be performed and the diagnosis missed.

Adolescent↗
PubMed1987

Carcinoembryonic antigen and milk-fat globule protein staining of malignant mesothelioma and adenocarcinoma of the lung.

Immunohistologic markers have been of considerable value in differentiating malignant mesothelioma from adenocarcinoma. Recently, staining for milk-fat globule (MFG) protein has been suggested as a useful diagnostic test for this separation, but subsequent reports have been conflicting, with some authors finding clearcut differences, while others showed similar marking of both tumor types. To examine this technique further, we studied lung carcinomas and mesotheliomas with commercially available anti-MFG, and compared these results with those obtained with anticarcinoembryonic antigen (CEA), a commonly used immunomarker of carcinoma. We found that carcinomas showed strong cytoplasmic staining for MFG and CEA; however, a greater percentage of carcinomas were more strongly positive for CEA than for MFG. Mesotheliomas did not, for the most part, stain strongly with either antibody. In addition, carcinomas from different hospitals stained differently for MFG, but not for CEA. We conclude that although strong cytoplasmic staining for MFG is a reasonably reliable indicator of carcinoma, CEA staining provides a better separation and is considerably easier to interpret in lung cancer specimens.

Adenocarcinoma↗
PubMed1987

Effects of cigarette smoke exposure on retention of asbestos fibers in various morphologic compartments of the guinea pig lung.

For investigation of mechanisms whereby smoking might potentiate asbestos-related disease, guinea pigs were given 0.5 mg UICC amosite by intratracheal instillation. Half the animals were subsequently exposed to cigarette smoke. Animals were sacrificed at 1 day, 7 days, and 1 month after exposure. Lungs were lavaged and macrophages separated from the lavage fluid. Lung fiber concentration, numbers of fibers in macrophages, and fiber sizes from tissue (TFs), macrophages (MFs), and macrophage-free lavagate (FFs) were determined by electron microscopy. Smoke-exposed animals retained greater numbers of fibers in lung tissue by 1 month but had greater total numbers of fibers in macrophages at all time periods. In both smokers and nonsmokers, fibers in the three morphologic compartments had distinctly different lengths: the longest fibers were found associated with the lung tissue; the macrophages always contained the shortest fibers; and the macrophage-free lavagate had fibers of intermediate size. However, fiber widths and aspect ratios did not show the same clear separation by anatomic compartment, suggesting that in both smoking and nonsmoking animals length is the size parameter which is most important in determining fiber clearance. Smoking did not affect the lengths of MFs but did produce a progressive reduction in the lengths of FFs and TFs with time. These data indicate that smoking causes a marked increase in the number of fibers retained in the lung within macrophages and suggest that either macrophage removal via the mucociliary escalator or macrophage mobility is impaired by cigarette smoke. However, smoking does not change the sizes of fibers in macrophages and does not appear to depress phagocytic capacity. These observations imply that failure of macrophage clearance and subsequent re-release of fibers into the medium may at least partially explain the changes in fiber sizes and eventual increases in tissue fiber concentrations in smoke-exposed animals.

Animals↗
PubMed1986

Fiber size and number in workers exposed to processed chrysotile asbestos, chrysotile miners, and the general population.

We analyzed chrysotile and chrysotile-associated amphibole (largely tremolite) asbestos fibers in 21 workers exposed to various types of processed (milled) chrysotile ore, 20 long-term chrysotile miners, and 20 members of the general population (controls). Significantly greater amounts of both chrysotile and tremolite were found in processed-ore workers and miners than in controls. On average, the mean fiber lengths and aspect ratios for the mining and processed-ore-exposed workers were similar and were significantly greater than the values seen in the controls; within the processed-ore group, there was a marked variation in these parameters, and some workers appeared to be exposed to fairly long, thin fibers. It was found empirically that the fiber size data, and to a lesser extent the concentration data, could be used to classify workers accurately into those with processed-ore exposure and controls. We conclude that fiber sizes in the lungs of processed-ore-exposed workers are similar to those of chrysotile miners and are considerably longer than those found in the general population; some processed-ore workers have longer fibers which might be responsible for higher disease incidences in certain working groups; tremolite accompanies chrysotile in a variable proportion of workers exposed to processed chrysotile products and might be important in the genesis of mesothelioma in such workers; and mineralogic analysis will usually detect exposure even when chrysotile has largely disappeared from lung tissue.

Air Pollutants, Occupational↗
PubMed1986

Malignant mesothelioma caused by childhood exposure to long-fiber low aspect ratio tremolite.

A 41-year-old man was found to have a malignant mesothelioma of the pleura. During childhood in Corsica, he had been exposed at home to chrysotile ore from the Canari mine. Analysis of lung mineral content revealed background levels of chrysotile but an elevated level of tremolite and actinolite asbestos. The latter had a geometric mean length of 3.7 microns, a value considerably longer than we have found for tremolite and actinolite from Quebec chrysotile miners but roughly the same as the mean length of amosite and crocidolite in workers with occupational amphibole exposure. No tremolite or actinolite fibers of length greater than 8 microns microns and width less than 0.25 micron were observed. The mean aspect ratio of the tremolite and actinolite fibers was 7, a value similar to that found in chrysotile miners with mesothelioma but considerably less than the mean aspect ratio of amosite and crocidolite from those with occupational exposure. These data suggest that long-fiber tremolite is a potential mesothelial carcinogen in humans, and that fiber length is more important than fiber aspect ratio in this regard.

Adult↗
PubMed1986

Asbestos bodies and the diagnosis of asbestosis in chrysotile workers.

It has been suggested that because chrysotile asbestos forms asbestos bodies poorly, use of the traditional histologic requirements (diffuse interstitial fibrosis plus asbestos bodies) for the diagnosis of asbestosis, may lead to an underdiagnosis of this condition in workers exposed only to chrysotile. We examined lungs from 25 chrysotile miners with diffuse interstitial fibrosis. Asbestos bodies were found easily in histologic section using hematoxylin and eosin stains in all cases. Mineralogic analysis of four cases showed that 46 of 72 (64%) bodies isolated and examined contained chrysotile cores, and 21 of 72 (29%) bodies contained cores of the amphiboles tremolite and actinolite. By contrast, tremolite and actinolite constituted the majority of uncoated fibers in these cases. The mean length for bodies formed on chrysotile was 35 micron, and for bodies formed on tremolite or actinolite, 36 micron. We conclude that (1) the usual histologic criteria for the diagnosis of asbestos are applicable to chrysotile-exposed workers; (2) in workers with occupational chrysotile exposure, bodies form readily on this mineral; and (3) asbestos bodies in these lungs reflect the presence of long asbestos fibers.

Asbestos↗
PubMed1986

Pulmonary capillary hemangiomatosis.

Pulmonary capillary hemangiomatosis (PCH) is a rare cause of pulmonary hypertension; only three cases have been reported. Four additional cases are described in this report. All of the patients in this study presented with signs and symptoms of pulmonary hypertension, and in none was a correct morphologic diagnosis made during life. Histologically, the most striking feature was the presence of numerous cytologically benign thin-walled capillary-sized blood vessels proliferating diffusely through alveolar walls and in and around larger vessels and airways. Venous infiltration was associated with intimal fibrosis and secondary veno-occlusive disease (VOD). Because of the presence of hemorrhage, the apparent interstitial widening and inflammation, and the venous changes, the condition in these cases was initially misdiagnosed as interstitial fibrosis or VOD. However, the identification of proliferating and invasive capillaries, which are unique to PCH, led to the correct diagnosis. Although the nature of PCH is unknown, it behaves like a low-grade vascular neoplasm.

Adolescent↗
PubMed1986

Chronic necrotizing pulmonary aspergillosis mimicking bronchocentric granulomatosis.

We present a case of slowly progressive Aspergillus infection occurring in a partially immunocompromised host. The histologic pattern mimicked bronchocentric granulomatosis as seen in allergic bronchopulmonary aspergillosis, but the clinical history, spread of disease in the face of steroid therapy, peculiar granulomatous response to the organisms, and large numbers of organisms present suggest that this was really a case of chronic necrotizing pulmonary aspergillosis. These entities must be distinguished because their therapy, prognosis, and clinical significance are totally different.

Aspergillosis↗
PubMed1986

Mammary fibroadenoma with multinucleated stromal giant cells.

We have studied an otherwise typical mammary fibroadenoma in a 42-year-old female in which numerous, bizarre, mitotically inactive, multinucleated giant cells were present throughout the stroma. Immunohistochemical and ultrastructural studies confirmed the mesenchymal, specifically fibroblastic, nature of the giant cells. Cells of this type, which are more commonly an incidental finding within the interlobular stroma of the breast, are benign, and should not be mistaken for malignant cells on microscopic examination.

Adult↗
PubMed1986

Smoking inhibits asbestos clearance.

To determine whether smoking affects the clearance of asbestos fibers, guinea pigs were given amosite asbestos by intratracheal instillation and divided into 3 groups: (1) nonsmokers, (2) animals exposed to smoke only after asbestos instillation, and (3) animals exposed to smoke both before and after asbestos instillation. Asbestos fiber concentrations and sizes were measured at 1 wk and 1 month after exposure. Between 1 wk and 1 month the asbestos burden in nonsmokers decreased on average 6-fold, whereas both smoking groups failed to show a significant decrease. Over this time period, the mean length of retained fibers increased in the nonsmokers but decreased in both smoking groups. This phenomenon was seen in tissue samples and lavage samples, although lavaged fibers were consistently shorter than tissue fibers. We conclude that in this model, cigarette smoking impedes asbestos clearance, largely by increasing retention of short fibers. This increased pulmonary fiber burden may be important in the increased disease rate seen in asbestos workers who smoke.

Animals↗
PubMed1986

Lung asbestos content in long-term residents of a chrysotile mining town.

The effects of long-term exposure to very small amounts of chrysotile asbestos are controversial. To examine this problem, the lung asbestos content from 7 long-term (25 yr and greater) residents of Thetford Mines, Quebec, who were never employed in the chrysotile mining and milling industry, was analyzed. Thetford Mines is a chrysotile mining town with a demonstrated ambient atmospheric concentration of chrysotile asbestos approximately 200 to 500 times that in urban areas of North America. Data on the residents' lungs were compared with those obtained from 20 long-term (25 yr and greater) chrysotile industry workers from Thetford Mines and 20 members of the general population of Vancouver. The median concentrations of chrysotile and tremolite in the Thetford residents were only about one fiftieth of those of the chrysotile workers, but about 10 times that of the population of Vancouver. Because long fibers of asbestos are generally thought to be more dangerous than short ones are, the sizes of fibers from these 3 groups were also examined. The fiber size distribution of the asbestos from the Thetford residents was significantly longer than that of the Vancouver population, and resembled that of the chrysotile workers. Because epidemiologic studies have consistently failed to find an increased respiratory disease incidence in lifelong residents of Quebec chrysotile mining towns who were never employed in the chrysotile industry, these findings imply that even asbestos burdens much higher, and fiber size distributions much longer, than those of the general population of most North American cities, are not associated with demonstrable pathologic effects.

Aged↗
PubMed1986

Pathophysiologic correlations in asbestos-induced airway disease in the guinea pig.

To determine whether asbestos-induced changes in the structure of the walls of small airways might be associated with abnormalities of pulmonary function, guinea pigs were given 10 mg of amosite asbestos (test group) or saline (control group) by intratracheal instillation. Pulmonary function tests performed 6 months later revealed significant increases in FRC, RV, and TLC in the test group. Measurement of airway wall thickness showed that both membranous and respiratory bronchioles were significantly thickened in the test group; this group also had airways of smaller internal diameter than the controls. Analysis for lung collagen content as hydroxyproline showed a 50% increase in the asbestos exposed animals. There was, however, only minimal and very focal interstitial fibrosis (asbestosis) in the lung parenchyma. Analysis of fiber size indicated that the fibers obtained by digestion of the tissue or from the lavage fluid were significantly longer and wider than those in the original asbestos sample; however, the tissue contained considerably larger fibers than the lavage fluid. We conclude that: Asbestos can produce airway fibrosis and narrowing causing air trapping on pulmonary function examination; this process occurs in the absence of significant interstitial fibrosis of the parenchyma (asbestosis), implying that abnormalities of pulmonary function which are consistent with airflow obstruction in asbestos exposed animals can be caused by pathologic changes in the small airways alone; long asbestos fibers are preferentially retained in the lung, and the longest fibers appear to be in a compartment inaccessible to lavage, presumably, in this model, in airway walls. Enhanced penetration of long fibers into tissue may be one reason why long fibers are more pathogenic than short ones.

Animals↗
PubMed1986

Cigarette smoke increases the penetration of asbestos fibers into airway walls.

For study of the penetration of asbestos fibers into airway walls, guinea pigs were given amosite asbestos by intratracheal instillation. Half of the animals were also exposed to cigarette smoke. Animals were sacrificed at 1 week and 1 month, and numbers of fibers in airway walls were counted in histologic sections. In both smoke-exposed and nonexposed groups, numbers of fibers per square millimeter of airway wall increased from 1 week to 1 month in the respiratory bronchioles. At each time period, smoke-exposed animals had significantly higher numbers of fibers in the airway walls, compared with nonexposed animals. It is concluded that 1) continued transport of fibers into interstitial tissues may be the reason that asbestosis can progress after cessation of exposure; 2) cigarette smoke increases the penetration of fibers into airway walls. This effect may play a role in the increased incidence of disease seen in smoking, compared with nonsmoking, asbestos workers.

Animals↗
PubMed1985

Malignant mesothelioma in British Columbia in 1982.

All cases newly diagnosed by a pathologist in 1982 in British Columbia as a malignant mesothelioma of the pleura or peritoneum were reviewed. In men there were 17 cases (incidence rate, 17.0/million/year), and in women 2 cases (1.9/million/year). A history of asbestos exposure (largely in shipyards, construction, or insulation work) was obtained for 14 of 15 men, and 0 of 1 woman. Mineralogic analysis of lung on 6 of the men confirmed that the tumor was associated in every instance with exposure to amosite and crocidolite asbestos; some patients also had elevated levels of tremolite asbestos, presumably reflecting exposure to a chrysotile asbestos product. No unusual levels of asbestos were found in the lungs of the one woman studied. These data show that the incidence rate of mesothelioma in British Columbia has increased nearly six times for men compared to the period 1969 to 1975, but has remained roughly unchanged for women. Almost all of the cases in men in this series could be linked to asbestos exposure.

Asbestos↗
PubMed1985

Mineral particles, mineral fibers, and lung cancer.

The total fibrous and nonfibrous mineral content of the lung has been analyzed in a series of 14 men with lung cancer but no history of occupational dust exposure, and in a series of 14 control men matched for age, smoking history, and general occupational class. The lung cancer patients had an average of 525 +/- 369 X 10(6) exogenous mineral particles and 17.4 +/- 19.6 X 10(6) exogenous mineral fibers/g dry lung, while the controls had averages of 261 +/- 175 mineral particles and 4.7 +/- 3.2 X 10(6) mineral fibers/g dry lung. These differences are statistically significant for both particles and fibers. Kaolinite, talc, mica, feldspars, and crystalline silica comprised the majority of particles of both groups. Approximately 90% of the particles were smaller than 2 micron in diameter and approximately 60% smaller than 1 micron; the mean particle size in the cancer group was 1.1 +/- 0.2 micron and in the control group 1.3 +/- 0.2 micron. In both groups, patients who had smoked more than 35 pack years had greater numbers of particles than patients who had smoked less than 35 pack years. It is concluded that, in this study, lungs from patients with lung cancer had statistically greater numbers of mineral particles and fibers than lungs from controls, and that smoking influences total long-term retention of particles from all sources.

Aged↗
PubMed1985

S-100 staining in the diagnosis of eosinophilic granuloma of lung.

The authors used immunohistochemical staining for S-100 protein to search for Langerhans cells in 7 cases of pulmonary eosinophilic granuloma (EGL) and in 18 cases of other pulmonary processes (including reactive eosinophilic pleuritis, chronic interstitial pneumonias, eosinophilic pneumonia, and nonspecific scars), which can produce diagnostic confusion with EGL. Qualitatively, Langerhans cells were found in almost every disease. However, cases of active or resolving EGL showed greater than 75 such cells/10 high-power fields (hpf), often appearing as densely packed aggregates (a virtually diagnostic feature), while all other conditions, including completely scarred EGL, showed fewer than 35 Langerhans cells/10 hpf, and the cells were scattered through the parenchyma. The authors conclude the following: (1) Langerhans cells participate in many types of inflammatory process in the lung, and hence the mere presence of Langerhans cells is not diagnostic of EGL; (2) S-100 staining with quantitation of Langerhans cells is a useful adjunct in the diagnosis of active and resolving EGL.

Eosinophilic Granuloma↗