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Biomedical subjects

W N Rom

Publications and source records attributed to W N Rom.

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

Exaggerated spontaneous release of platelet-derived growth factor by alveolar macrophages from patients with idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis is a fibrotic lung disease characterized by an increased number of mesenchymal cells in the alveolar walls. Alveolar macrophages constitutively express low levels of c-sis, the protooncogene coding for the B chain of platelet-derived growth factor, a protein with chemotactic and mitogenic activity toward mesenchymal cells. We therefore hypothesized that alveolar macrophages in patients with idiopathic pulmonary fibrosis may release increased amounts of platelet-derived growth factor, which might help to explain the accumulation of mesenchymal cells and the fibrosis of the lower respiratory tract in the disease. Evaluation of alveolar macrophages recovered from the lungs of patients with idiopathic pulmonary fibrosis demonstrated that these cells spontaneously released four times more platelet-derived growth factor than did alveolar macrophages recovered from normal persons (P less than 0.01). That the platelet-derived growth factor molecules were potentially active was shown by their chemotactic activity for smooth-muscle cells and their ability to act as a "competence" factor for fibroblast growth. These observations suggest the possibility that the accumulation of mesenchymal cells within the alveolar walls in patients with idiopathic pulmonary fibrosis may result partly from the exaggerated release of the potent mitogen platelet-derived growth factor by mononuclear phagocytes in the lower respiratory tract.

Biological Assay↗
PubMed1987

Characterization of the lower respiratory tract inflammation of nonsmoking individuals with interstitial lung disease associated with chronic inhalation of inorganic dusts.

The pneumoconioses, interstitial lung disorders resulting from the inhalation of inorganic dusts, are associated with chronic inflammatory processes in the lower respiratory tract. To characterize these inflammatory processes in relation to the pathogenesis of these disorders, we studied 39 nonsmoking individuals with long-term occupational exposures to inorganic dust and functional evidence of interstitial disease (asbestosis, n = 18; coal workers' pneumoconiosis, n = 15; silicosis, n = 6). In all 3 disorders, the inflammation was dominated by alveolar macrophages. Because a common feature of these interstitial lung diseases is concurrent injury and fibrosis of alveolar walls, we assessed whether these alveolar macrophages were spontaneously releasing mediators capable of giving rise to these changes. Alveolar macrophages from the study population were spontaneously releasing increased amounts of superoxide anion and hydrogen peroxide (both p less than 0.01 compared to normals), oxidants capable of injuring lung parenchymal cells. The alveolar macrophages were also spontaneously releasing significantly increased amounts of fibronectin and alveolar macrophage-derived growth factor (both p less than 0.01 compared to normals), mediators that act synergistically to signal fibroblast replication. Taken together, these findings define a major role for the alveolar macrophage in mediating the alveolar wall injury and fibrosis that characterize the common pneumoconioses and suggest that the alveolar macrophage is an important "target" for developing strategies designed to prevent loss of lung function in these individuals.

Adult↗
PubMed1987

Acute tropical pulmonary eosinophilia. Characterization of the lower respiratory tract inflammation and its response to therapy.

Although acute tropical pulmonary eosinophilia (TPE) is well recognized as a manifestation of filarial infection, the processes that mediate the abnormalities of the lung in TPE are unknown. To evaluate the hypothesis that the derangements of the lower respiratory tract in this disorder are mediated by inflammatory cells in the local milieu, we utilized bronchoalveolar lavage to evaluate affected individuals before and after therapy. Inflammatory cells recovered from the lower respiratory tract of individuals with acute, untreated TPE (n = 8) revealed a striking eosinophilic alveolitis, with marked elevations in both the proportion of eosinophils (TPE 54 +/- 5%; normal 2 +/- 5%; P less than 0.001) and the concentration of eosinophils in the recovered epithelial lining fluid (ELF) (TPE 63 +/- 20 X 10(3)/microliter; normal 0.3 +/- 0.1 X 10(3)/microliter; P less than 0.01). Importantly, when individuals (n = 5) with acute TPE were treated with diethylcarbamazine (DEC), there was a marked decrease of the lung eosinophils and concomitant increase in lung function. These observations are consistent with the concept that at least some of the abnormalities found in the lung in acute TPE are mediated by an eosinophil-dominated inflammatory process in the lower respiratory tract.

Adult↗
PubMed1986

Health effects among refrigeration repair workers exposed to fluorocarbons.

Refrigeration repair workers may be intermittently exposed to fluorocarbons and their thermal decomposition products. A case of peripheral neuropathy (distal axonopathy) in a commercial refrigeration repairman prompted an epidemiological investigation of the health of refrigeration repair workers. No additional cases of peripheral neuropathy were identified among the 27 refrigeration repair workers studied. A reference group of 14 non-refrigeration repair workers was also studied. No differences were noted between groups for the ulnar (motor and sensory), median (motor and sensory), peroneal, sural, or tibial nerve conduction velocities. Refrigeration repair workers reported palpitations and lightheadedness significantly more often than workers in the reference group. No clinical neurological or electroneurophysiological abnormalities were detected in eight refrigeration repair workers followed up for three years during continuous employment.

Adult↗
PubMed1986

Longitudinal evaluation of pulmonary function in copper smelter workers exposed to sulfur dioxide.

From 1973 to 1974, a longitudinal study of pulmonary function in 113 Utah copper smelter workers reported significant declines in FVC and FEV1 related to sulfur dioxide exposure. In 1980, we performed a 7-yr follow-up study, finding significant increases in FVC and FEV1. The 66 follow-up participants were similar to those 47 lost to follow-up with regard to age and initial pulmonary function. Subgroups of smelter workers with initial higher exposures to sulfur dioxide and FEV1 less than 90% predicted did not show an accelerated rate of decline. To reconcile these differences between the 2 studies, we reevaluated the spirometry curves from 1973 and 1974. All had short expiratory times, with none 6 s or longer, whereas all of the curves from the spirograms obtained in 1980 exceeded 6 s. In addition, from 1980 to 1983, we performed a longitudinal study of 48 of the original workers, finding small annual mean declines for FVC of 6 ml and FEV1 of 5 ml. Personal exposures to sulfur dioxide were not significantly different in 1982 than in 1976; thus, we were unable to corroborate the findings of the initial longitudinal study.

Copper↗
PubMed1985

Gallium-67 citrate imaging in underground coal miners.

Twenty-two underground coal workers with 27 or more years of coal dust exposure were studied with gallium-67 citrate (Ga-67) imaging. Radiographic evidence of coal workers pneumoconiosis (CWP) was present in 12 subjects. The Ga-67 scan was abnormal in 11 of 12 with, and 9 of 10 without, CWP. The Ga-67 uptake index was significantly correlated with total dust exposure (p less than 0.01) and approached significant correlation with the radiographic profusion of the nodules (0.10 greater than p greater than 0.05). There was no correlation between Ga-67 uptake and spirometric function, which was normal in this group of patients; furthermore, increased lung uptake of gallium did not indicate a poor prognosis in subjects no longer exposed to coal dust. While coal dust exposure may be associated with positive Ga-67 lung scan in coal miners with many years of coal dust exposure, the scan provided no information not already available from a careful exposure history and a chest radiograph. Since Ga-67 scanning is a relatively expensive procedure we would recommend that its use in subjects with asymptomatic CWP be limited to an investigative role and not be made part of a routine evaluation.

Aged↗
PubMed1985

Circulating immune complexes in asbestos workers.

Circulating immune complexes, rheumatoid factor, and antinuclear antibodies were evaluated in 25 asbestos insulation workers and 32 brick mason controls. There were 10 asbestos workers with radiographic parenchymal or pleural changes, consistent with their asbestos exposure. There were no differences in antinuclear antibodies or rheumatoid factor between asbestos workers and controls. The asbestos workers had significantly increased levels of IgG and IgA circulating immune complexes. There was a significant correlation between IgA circulating immune complexes and radiographic changes.

Adult↗
PubMed1985

Zeolite exposure and associated pneumoconiosis.

Naturally occurring zeolite minerals are aluminum silicates widespread in the earth's crust. Several of these minerals have fibrous forms and have been implicated as a possible cause of benign and malignant diseases of the lung and pleura in Turkey. This report describes a patient, living in an area of Nevada rich in zeolites, who presented with idiopathic pleural thickening and pulmonary fibrosis associated with extensive pulmonary deposition of zeolites.

Aluminum Silicates↗
PubMed1984

Basophilic stippling of red blood cells: a nonspecific finding of multiple etiology.

Basophilic stippling of red blood cells (BSC) has been noted in lead intoxication since 1899 and has been considered a classic laboratory sign of lead poisoning since that time. BSC are inclusions of aggregated ribosomes found only in the red blood cells and may be confused with siderotic (iron) granules. Heinz Bodies, or even reticulocytes. BSC are an inconstant finding in lead intoxication. In a review of peripheral blood smears from 1,000 consecutive internal medicine patients, we found BSC in 27%. These occurred in a variety of malignant, rheumatologic, hematologic, cardiovascular, and other diseases, frequently with an associated anemia. BSC may even be found in a small percentage of normal people; thus, it must be emphasized that BSC is a nonspecific finding. Furthermore, BSC has been replaced by blood lead (since the 1940s) and zinc protoporphyrin (since the 1970s) levels for biologic monitoring of lead-exposed workers.

Disease↗
PubMed1984

The use of asbestos-cement pipe for public water supply and the incidence of cancer in selected communities in Utah.

We tested the hypothesis that there is an association between the use of asbestos-cement piping for drinking water supplies and the incidence of gastrointestinal and kidney cancer. Cancer incidence in 14 Utah communities that had used predominantly asbestos-cement piping for transporting their drinking water supplies for 20 years or more were compared to 27 Utah communities that had never used asbestos-cement piping. Cancer incidence was tabulated for 11 cancer sites for the years 1967-1976. Increased Standard Incidence Ratios (SIRs) were found for cancer of the kidney in men (SIR 192) and leukemia (a control site) in women (SIR 203). No increased SIRs were found for the opposite sex at these sites or for the other gastrointestinal sites singly or in combination. There was no increase in age-adjusted cancer incidence for the 11 sites in 4 of the 14 study communities that had used asbestos-cement piping for 30 years or more. Limitations of the study were that the water supplies were nonaggressive, and leaching from the pipes was minimal if at all. Furthermore, the latent period for observation was very short, suggesting that these results should be considered preliminary.

Adult↗
PubMed1984

Pneumoconiosis and exposures of dental laboratory technicians.

One hundred and seventy-eight dental laboratory technicians and 69 non-exposed controls participated in an epidemiological respiratory study. Eight technicians who had a mean of 28 years' grinding nonprecious metal alloys were diagnosed as having a simple pneumoconiosis by chest radiograph. Mean values for per cent predicted FVC and FEV1 were reduced among male nonsmoker technicians compared to male nonsmoker controls; after controlling for age, there was also a reduction in spirometry with increasing work-years. An industrial hygiene survey was conducted in 13 laboratories randomly selected from 42 laboratories stratified by size and type of operation in the Salt Lake City, Utah metropolitan area. Personal exposures to beryllium and cobalt exceeded the Threshold Limit Values (TLVs) in one laboratory. Occupational exposures in dental laboratories need to be controlled to prevent beryllium-related lung disorders as well as simple pneumoconiosis.

Adult↗
PubMed1983

Lymphocyte sister chromatid exchange (SCE) frequencies in coke oven workers.

Lymphocyte sister chromatid exchange (SCE) frequencies were determined for 12 long-term coke oven workers and 12 other age-matched steelworkers with no coke oven work exposure. All study participants were nonsmokers. The exposed group had a mean of 28.9 years' exposure to the coke oven emissions. SCE frequencies for the exposed individuals ranged from 7.97 to 11.20 SCEs per cell while the control individuals ranged from 6.73 to 10.60 SCEs per cell. The mean SCE frequency for the exposed group was 9.54 +/- SD 1.15 SCEs per cell, and was 14% higher than the 8.35 +/- SD 1.09 SCEs per cell of the control group (p = .016). The long-term exposure to coke oven emissions experienced by the coke oven workers may be the explanation for this small difference.

Adult↗
PubMed1983

Antinuclear antibodies in Utah coal miners.

Antinuclear antibodies (ANA) were detected using a mouse kidney substrate in 69 of 238 (29 percent) underground Utah coal miners at a titer of 1:16. At titers of 1:4 and higher, 52 percent were positive. The majority had a speckled pattern and were not directed against any previously characterized antigens. Fifteen of 28 with high titer ANA had reduced complement. The ANA was more apt to be present in those with coal workers' pneumoconiosis (CWP), and as ANA titer increased, the percentage with CWP increased. The ANA increased with both age and coal mine dust exposure. It is hypothesized that ANA and CWP both result from long-term dust exposure, but that there is insufficient evidence to implicate ANA in the pathogenesis of CWP.

Age Factors↗