PubMed Health⌕ Search

Biomedical subjects

A Churg

Publications and source records attributed to A Churg.

At least 163 records · Page 9Linked to original sources
PubMed1983

Nonasbestos pulmonary mineral fibers in the general population.

Total pulmonary nonasbestos mineral content was determined for a series of 20 patients who had no occupational dust exposure. To extract mineral fibers, lung tissue was dissolved in bleach and the treated sediment transferred to the electron microscope grid. Mineral fibers were identified using electron diffraction and energy dispersive x-ray spectroscopy. The mean number of nonasbestos fibers, 106 X 10(3)/g wet lung, was almost identical to the mean number of asbestos fibers, 102 X 10(3)/g. Thirteen different species or groups of nonasbestos minerals were found: apatite accounted for 18% of the total and talc for 16%. All other forms accounted for less than 8% each. Silica was found in every lung, and talc in 19 of 20 lungs. Of the fibers, 86% were shorter than 5 microns, and most of the fibers had aspect ratios less than 15. No correlations were seen between numbers or types of fibers and age, sex, or smoking. It is concluded that (1) substantial numbers of nonasbestos fibers are present in lungs of the general population. Most of these fibers are short and of low aspect ratio; and (2) by phase microscopy one is as likely to observe nonasbestos as asbestos fibers in these preparations, indicating that light microscopic methods are not suitable for this type of analysis. These data provide a baseline for comparison with patients believed to have a mineral fiber-related disease.

Adult↗
PubMed1983

Mesothelioma in pet dogs associated with exposure of their owners to asbestos.

Pet dogs with spontaneous mesothelioma were used to identify environmental exposures that might increase their owner's risk of asbestos-related disease. These animals share man's domicile environment, yet do not indulge in activities (e.g., smoking, working) which confound interpretation of epidemiologic studies. Eighteen histologically confirmed canine mesotheliomas were diagnosed at the Veterinary Hospital of the University of Pennsylvania, Philadelphia, from April 1977 to December 1981. Sixteen owners of cases and 32 owners of age, breed, and sex-matched controls were interviewed to determine their occupation and medical history and their dog's medical history, life style, diet, and exposure to asbestos. An asbestos-related occupation or hobby of a household member and use of flea repellents on the dog were significantly associated with mesothelioma. In addition, there was a trend indicating an increased risk of mesothelioma with an urban residence. Lung tissue from three dogs with mesothelioma and one dog with squamous cell carcinoma of the lung had higher levels of chrysotile asbestos fibers than lung tissue from control dogs. These findings indicate that well-designed epidemiological studies of spontaneous tumors in pet animals may provide insight into the role of environmental factors in human cancers and serve as a valuable sentinel model to identify environmental health hazards for humans.

Animals↗
PubMed1983

Small-airway lesions in patients exposed to nonasbestos mineral dusts.

Small-airway lesions were identified in histologic sections from the lungs of seven workers with histories of exposure to nonasbestos dusts. The lesions consisted of deposits of fibrous tissue, often accompanied by pigment, in the walls of membranous and respiratory bronchioles and alveolar ducts. Comparison with a matched population of persons with no dust exposure revealed that the changes in the respiratory bronchioles and alveolar ducts were morphologically distinctive and could be used to diagnose the lesions. Structurally, these lesions were very similar to those described in the airways of asbestos workers, although comparison with the authors' previous results indicated that the number of severely affected airways was less in the nonasbestos dust group. Mineralogic analysis indicated that these abnormalities were produced by a variety of different dusts including silica, iron oxide, and aluminum oxide, and that occult asbestos exposure, although possible in three of the cases, was most likely not a primary cause of disease. The authors suggest that this lesion, which they call mineral dust airways disease, is a nonspecific reaction of the small airways to inorganic particulates. The presence of such changes casts considerable doubt on the theory that small-airway abnormalities in asbestos workers are the earliest form of asbestosis.

Aged↗
PubMed1983

Pulmonary angiitis and granulomatosis revisited.

Re-examination of the pathologic and clinical features of the entities traditionally classified under the heading "pulmonary angiitis and granulomatosis" indicates that there is little advantage in retaining this artificial category and that these entities should be considered variants of diseases to which they are actually related. Wegener's granulomatosis and allergic angiitis and granulomatosis appear to be examples of true systemic vasculitides in which the lung is a predominant but not the only or even the most important site of involvement. Wegener's granulomatosis may manifest with involvement limited to lung, a form that has been called limited Wegener's; however, many or most such cases progress to classic disease involving kidney and often upper respiratory tract. Similarly, Wegener's granulomatosis may present with disease limited initially to the upper respiratory tract (a form of midline granuloma); this process may also spread to involve lung and kidney. It seems unlikely that limited Wegener's is truly a separate disease category. Evaluation of the pathologic and clinical features of necrotizing sarcoid granulomatosis indicate that it very much resembles ordinary sarcoid in most histologic features, in the nature of extrapulmonary involvement, and in its clinical course and that it probably corresponds to the clinical--radiographic entity of nodular sarcoid. Lymphomatoid granulomatosis appears to have little relationship to the other members of the angiitis and granulomatosis group; its behavior and histologic features are those of a lymphoproliferative disorder that in most cases is or becomes histiocytic lymphoma. Some cases of so-called benign lymphocytic angiitis also fall into this category; the remainder appear to represent a variety of completely unrelated pathologic processes. Last, bronchocentric granulomatosis is most commonly one of the histologic manifestations of allergic bronchopulmonary aspergillosis, although it is likely that other agents or processes produce the same histologic pattern. Although the presence of a common set of pathologic features makes the concept of angiitis and granulomatosis attractive from a morphologic point of view, there is minimal clinical similarity among them, and these diseases appear to be totally separate entities.

Acute Disease↗
PubMed1983

Progressive massive fibrosis of the lung secondary to intravenous injection of talc. A pathologic and mineralogic analysis.

We present a patient with a history of heroin addiction and 19 years of methadone maintenance who died of respiratory failure following nine years of slowly progressive dyspnea. During this nine-year period, chest x-rays consistently had revealed large, bilateral densities having the appearance of progressive massive fibrosis (PMF). At autopsy the lungs exhibited corresponding areas of dense, gritty consolidation, which microscopically showed an active granulomatous reaction with associated vascular obliteration. Throughout the lesions were refractile and birefringent plates of particulate material. Interstitial, perivascular, and vascular granulomas also were noted in the periphery of the lung. X-ray energy spectroscopy and diffraction studies of the particulates confirmed the presence of talc at levels of 540 X 10(6) particles/g of dried tissue in the mass lesion and 96 X 10(6)/g in the peripheral lung. Smaller numbers of silica particles also were identified. Approximately 30% of the talc particles were greater than 5 mu in maximum dimension, a finding consistent with intravenous delivery. Particles larger than 15 mu were only found in the mass lesion. We conclude that massive granulomatous lesions with the radiographic appearance of PMF can occur in association with intravenous injection of talc. We suggest that particle size and cumulative particle load are important in the pathogenesis of these lesions.

Electron Probe Microanalysis↗
PubMed1983

Bronchopulmonary dysplasia in the adult.

We describe 3 patients with adult respiratory distress syndrome that eventuated in a pathologic picture of honeycomb lung and a radiographic picture of variably cystic lung super-imposed on a background of diffuse alveolar infiltrates. All 3 patients had been treated with unusually high pressures of PEEP as well as high concentrations of oxygen for long periods of time (3 to 7 wk). Microscopically, the cystic structures in our patients appeared to be derived from collapse and fibrosis of the alveolar parenchyma with dilatation of the alveolar ducts. We suggest that this process is morphologically and radiographically similar to bronchopulmonary dysplasia as seen in the newborn.

Adolescent↗
PubMed1983

Asbestos fiber content of the lungs in patients with and without asbestos airways disease.

I analyzed the total pulmonary asbestos burden in the lungs of 9 chrysotile miners who had asbestos airways disease (so-called "early asbestosis") but no evidence of classic asbestosis (interstitial fibrosis) on pathologic examination. The results were compared with values found for 9 miners matched for age, sex, smoking, and work length who had no histologic evidence of asbestosis or asbestos airways disease. The mean value for chrysotile fibers in the airway disease group was 47 X 10(6)/g dried lung, compared with 23 X 10(6) in the group without lesions (p less than 0.04). For contaminant amphiboles, probably derived from the chrysotile ore (tremolite, actinolite, anthophyllite), the corresponding values were 106 X 10(6) versus 58 X 10(6) (p less than 0.06), and for total asbestos fibers, 153 X 10(6) versus 81 X 10(6) (p less than 0.06). There was a strong correlation between amount of chrysotile and amphibole for each case, suggesting that the amphibole was probably a good measure of the original (but no longer present) chrysotile burden. No differences were seen between the 2 groups with regard to fiber size distribution, aspect ratios, or fiber widths. I conclude that the overall differences in fiber concentration between the 2 groups, although significant, are sufficiently small enough to suggest that other factors may be involved in the genesis of small airway lesions.

Aged↗
PubMed1982

Fiber counting and analysis in the diagnosis of asbestos-related disease.

Analysis of numbers and types of asbestos fibers present in lung tissue may provide insights into the pathogenesis of asbestos-induced disease, as well as diagnostic information concerning the relationship of a given lesion to asbestos exposure. This type of analysis requires extraction of fibers and asbestos bodies from lung tissue, preferably by means of a digestion-and-concentration technique, and examination with a combination of electron optical techniques, including electron diffraction and energy-dispersive x-ray spectroscopy. The combination permits definitive identification of asbestos fibers. Asbestos bodies have been shown to contain asbestos no matter what population they are found in, but they appear to be of value in ascertaining unusual exposure only when present in very large numbers. Numbers of asbestos bodies markedly underestimate total numbers of fibers present in lung. In patients from the general population, the mean number of asbestos fibers is about 1 X 10(6)/g dry lung; of this number, more than 80 per cent are fibers of chrysotile less than 5 microns long. Patients in the general population who have pleural plaques have about the same total number of fibers, but their lungs contain about a 50-fold increase in long thin amphibole fibers of commercial origin. Patients who have asbestosis and most patients who have mesothelioma have 100 to 200 X 10(6) fibers/g dry lung; the grade of asbestosis appears to be related to total fiber content. Occasional patients may develop mesotheliomas with much smaller fiber burdens. Both benign and malignant pleural diseases appear to be closely related to the presence of long thin amphibole fibers. Analysis of pulmonary fiber burden suggest that asbestos-related disease is not merely a matter of total numbers of fibers present, but that factors such as fiber type and size are equally important.

Asbestos↗
PubMed1982

Asbestos fibers and pleural plaques in a general autopsy population.

It has been claimed that symmetric lower zone pleural or diaphargmatic plaques are markers of asbestos exposure both in asbestos workers and the general population. In this study, total pulmonary asbestos burden was analyzed for 29 patients selected because pleural plaques were found at autopsy, and the results were compared with values obtained for 25 patients who had no occupational asbestos exposure. The average number of asbestos bodies in the plaque groups was 1732/g wet lung, and in the control group, 42/g wet lung. Uncoated asbestos fibers were extracted from lung and counted, measured, and identified by morphologic examination, electron diffraction, and energy-dispersive x-ray spectroscopy. The total number of fibers/per gram wet lung in the plaque group (114 x 10(3)) was similar to that in the control group (99 x 10(3), as was the number of chrysotile fibers (51 x 10(3) versus 29 x 10(3)). However, the plaque patients had a marked increase in the number of the commercially used high aspect ratio amphiboles, amosite and crocidolite (50 x 10(3) versus 1 x 10(3). A retrospective history of fairly certain asbestos exposure was obtained for 16 of the plaque patients, and such a history correlated strongly with increased numbers of commercial amphiboles in lung. It is concluded that 1) in this general autopsy population, two subgroups of patients are present. About one half of the patients appear to have developed pleural plaques as a result of asbestos exposure, while the etiology of the plaques in the other half is unclear; 2) the presence of pleural plaques correlates with a modest (50-fold) increase in numbers of long high-aspect ratio commercial amphiboles in lung tissue but does not correlate with numbers of chrysotile fibers, noncommercial amphiboles, or the total number of asbestos fibers; 3) asbestos-induced lesions are related to a complex set of mineralogic parameters and not to mere numbers of fibers in lung.

Asbestos↗
PubMed1981

Intravascular and sclerosing bronchioloalveolar tumor. A pulmonary sarcoma of probable vascular origin.

A case of intravascular and sclerosing bronchioloalveolar tumor (IVSBAT) studied by light microscopy and electron microscopy is reported. Light microscopy revealed typical nodules composed of plump tumor cells in the peripheral regions and central areas of hyalinization. Histochemical examination revealed that the matrix material contained hyaluronic acid. Around the periphery of the nodules, tumor cells and matrix material were observed within the alveolar walls. Tumor was also present in numerous small bood vessels and lymphatics. Electron microscopy demonstrated that the tumor cells were polygonal or elongated and were connected by small junctions. The cytoplasm was filled with fine filaments, and dense bodies typical of those seen in smooth muscle cells were occasionally observed. Pinocytotic vesicles and basement membranes were also present. Some cells formed vessel-like lumina. Rows of tumor cells were identified within alveolar walls where they at first proliferated without disturbing the overall architecture; increasing numbers of tumor cells and matrix material gradually widened the alveolar walls, and the tumor finally expanded into the alveolar spaces. The ultrastructural features of the tumor cells are consistent with an origin form pericytes or endothelial cells; we suggest that IVSBAT is actually a sarcoma of vasoformative cells which arises within the alveolar walls, perhaps in multicentric fashion. We propose that the tumor be renamed "sclerosing interstitial vascular sarcoma".

Humans↗
PubMed1981

Severe pulmonary involvement in mixed connective tissue disease.

Pulmonary involvement in mixed connective tissue disease has been considered a benign manifestation that is easily treated with corticosteroids. We followed 5 patients who had mixed connective tissue disease and severe, rapidly progressive, lung disease. Two types of lung disease were found, interstitial lung disease and pulmonary hypertension. Histologic sections from our patients were compared with sections from patients who had interstitial lung disease and systemic lupus erythematosus or pulmonary hypertension and scleroderma. Although clinical presentations were similar, the immunofluorescent and electron microscopic findings for interstitial lung disease were somewhat different in patients with systemic lupus erythematosus. Histologic findings for pulmonary hypertension appeared different in patients with mixed connective tissue disease and patients with scleroderma. For patients with either type of lung disease, corticosteroid therapy proved inadequate, but nearly cytotoxic therapy may be beneficial.

Adult↗
PubMed1980

Successful therapy of an ACTH-producing gastric carcinoid APUD tumor: report of a case and review of the literature.

A case of a patient with a metastatic ACTH (adrenocorticotrophic hormone)-producing gastric carcinoid APUD (amine precursor uptake and decarboxylation) tumor is presented. The patient presented with Cushing's syndrome and very high levels of ACTH. The Cushing's syndrome was controlled medically, and when the patient deteriorated clinically she received treatment with a combination of BCNU, adriamycin, and ftorafur. She responded dramatically with marked clinical improvement and normalization of plasma ACTH levels. The current status of the APUD cell concept is discussed, with its overall implications for treatment of this group of malignancies.

Adrenocorticotropic Hormone↗
PubMed1980

Further observations on cytoplasmic hyaline in the lung.

Cytoplasmic hyaline material resembling Mallory's alcoholic hyaline has previously been described in pulmonary alveolar cells of patients with asbestosis. We present 14 new cases of cytoplasmic hyaline found in patients with a variety of processes causing damage to the alveolar lining; these include cases of radiation pneumonia, diffuse interstitial fibrosis, organizing bacterial pneumonia, as well as asbestosis. Hyaline was found only in the setting of an unusual type II cell change, which ultrastructurally appeared to represent squamous metaplasia. We conclude that pulmonary cytoplasmic hyaline is not specific for asbestosis but rather is a nonspecific reaction to injury;

Adult↗