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Biomedical subjects

A Dewar

Publications and source records attributed to A Dewar.

At least 91 records · Page 5Linked to original sources
PubMed1983

Ultrastructural changes in bronchoalveolar lavage cells in sarcoidosis and comparison with the tissue granuloma.

The authors undertook this study to determine whether there were any morphologic changes in bronchoalveolar lavage lymphocytes and macrophages in sarcoidosis and, in particular, to determine whether changes described previously in the mononuclear phagocytes of sarcoid granulomas were also evident in such cells obtained by lavage. Lavage cells from 28 sarcoidosis patients were studied by transmission electron microscopy and compared with lavage cells from 17 control subjects and with lung tissue granulomas from 5 sarcoidosis patients. Interactions between mononuclear phagocytes, especially subplasmalemmal linear densities, and between these cells and lymphocytes were observed in both the tissue granulomas and lavage specimens from sarcoidosis patients. Subplasmalemmal linear densities were never observed in control lavage specimens. Fully developed epitheloid cells were not identified in lavage specimens, but differences were nevertheless found between the lavage cells from sarcoidosis patients and control subjects: in particular, alveolar macrophages in sarcoidosis were larger and showed better developed pseudopodia, more marked polarity, less nuclear heterochromatin, and lysosomes that were larger and more numerous but less electron-dense than normal. Lymphocytes were also enlarged and contained more lysosomes. It is concluded that although there are only a few similarities between the cells of the granuloma and those obtained by bronchoalveolar lavage in sarcoidosis, there are noticeable differences between the lavage cells of sarcoidosis patients and control subjects. In sarcoidosis, a variable proportion (10-70%) of the lavage cells show morphologic features of "activation."

Adult↗
PubMed1982

One very rare and one new tracheal tumour found by electron microscopy: glomus tumour and acinic cell tumour resembling carcinoid tumours by light microscopy.

Tracheal tumours were removed surgically from two patients and diagnosed as carcinoid tumours by routine light microscopy. At a later date, electron microscopy was performed on stored tumour tissue and no neurosecretory granules were found in either case. One showed features of a glomus tumour and the other of an acinic cell tumour. Only two glomus tumours appear to have been reported previously in the trachea, and no acinic cell tumours. Electron microscopy is thus sometimes of great assistance in diagnosing accurately unusual tumours of the lower respiratory tract.

Carcinoid Tumor↗
PubMed1982

Transitory ultrastructural abnormalities of cilia.

We report a patient with chronic respiratory tract disease and ultrastructural abnormalities of nasal cilia at first interpreted as being consistent with a primary ciliary defect. Subsequent sampling of nasal ciliated epithelium from the same area failed to reveal the defects of structure. Abnormalities of ciliary ultrastructure found on a single occasion, especially in the presence of acute inflammation, should be interpreted with caution.

Child↗
PubMed1981

Evidence of increased histamine levels of lung lavage fluids from patients with cryptogenic fibrosing alveolitis.

In this study we report a significant increase in histamine in lung lavage fluids from a group of 33 patients with lone cryptogenic fibrosing alveolitis (lone CFA), and from a group of 13 patients having CFA in association with other connective tissue disorders, when compared with findings for 13 smoking patient controls without peripheral lung disease (P less than 0.001, P less than 0.05 respectively). The increases were independent of smoking or treatment. Significant correlations were obtained between the raised histamine levels in CFA and increased levels of albumin and increased counts of neutrophils and eosinophils in the lavage fluids, and with more pronounced fibrosis in CFA lung biopsies.. Thus histamine is associated with features of inflammation relating to progressive or more severe disease. No significant increase in histamine was observed in a group of 22 patients with sarcoidosis, although 21 had evidence of disease involving the lung parenchyma. There were, however, significantly higher levels in the patients with X-ray evidence of upper lobe contraction, suggestive of "fibrosis" (P less than 0.025). The levels also showed a correlation with increasing counts of lavage neutrophils (P less than 0.005), a feature also associated with X-ray evidence of contraction in this group. Mast cells were readily identified in biopsies from 12 CFA patients suggesting that these cells may provide one possible source of histamine in CFA lungs. These observations raise the question whether histamine, and/or possibly other substances derived from mast cells, plays any role in amplifying inflammation associated with pulmonary fibrosis.

Adult↗
PubMed1980

Bronchoalveolar lavage fluid cell counts in cryptogenic fibrosing alveolitis and their relation to therapy.

Bronchoalveolar lavage was used to sample inflammatory cells from the lungs of 51 patients with cryptogenic fibrosing alveolitis (CFA) (24 smokers, 12 ex-smokers, and 15 non-smokers). The smokers with CFA have been compared with 15 smoking control subjects in whom there was no radiographic abnormality or clinical evidence of chronic bronchitis. Significantly lower volumes of lavage fluid were recovered from the smokers with CFA (p < 0.001) and the fluid contained lower percentages of macrophages (p < 0.01), reflecting increased percentages of eosinophils (p < 0.001) and neutrophils (p < 0.01). Similar changes were seen in the ex-smokers and non-smokers. There was also an increase in the percentages of lymphocytes when the whole group of CFA patients was compared with the control subjects (p less than or equal to 0.05). No significant differences were found when patients with "lone" CFA were compared with those having associated systemic disease. The only feature distinguishing smokers from non-smokers with CFA was the presence of pigmented cytoplasmic inclusions in the macrophages from the smokers (p < 0.001). However, there were lower numbers of pigmented macrophages in the smoking CFA patients by comparison with the control subjects suggesting either a change in phagocytic capacity or turnover rate in this disease. Profiles of differential cell counts in individual patients showed that increases of eosinophils over 3% or neutrophils over 4% or both with lymphocyte counts of less than 11% related to a poor clinical response to corticosteroids, but lymphocyte percentages greater than 11% related to improvement (p < 0.05).

Adult↗
PubMedDate not supplied

Identification of inorganic dust particles in bronchoalveolar lavage macrophages by energy dispersive x-ray microanalysis.

This study shows that energy dispersive x-ray microprobe analysis to identify and quantify intracellular particles in macrophages obtained by the minimally invasive method of bronchoalveolar lavage (BAL) can detect inorganic dust exposures of many different kinds. Bronchoalveolar lavage macrophages from 22 patients have been examined. Twelve patients had occupational exposure to asbestos, talc, silica, hard metal or printing ink, while 10 had no known history of dust exposure. X-ray microprobe analysis identified particles which related to the known exposures, superimposed on a background of other particles related to smoking (kaolinite and mica) or to the general environment (silicon, titanium, and iron). The particle identification provided useful objective confirmation of the known exposures, except for silica, which could not be distinguished from the general background levels. X-ray microanalysis using BAL macrophages can be helpful for clarification of mixed dust exposures, to identify particles when light microscopy indicates retained dust in patients with no known history of exposure, and to monitor retained particles after removal from exposure.

Adult↗
PubMedDate not supplied

Tracheal potential difference in the reserpine and isoproterenol rat models of cystic fibrosis.

Basic research into cystic fibrosis (CF) has been hampered by the lack of a suitable animal model. Reserpinized or isoproterenol-treated rats have been proposed as models because they exhibit certain morphological and physiological features characteristic of CF. Recent evidence suggests that abnormal epithelial transport of Na+ [corrected] and Cl- may underlie pathogenesis, defects that may contribute to the markedly more negative transepithelial electrical potential differences (PD) recorded in CF airways compared with controls. To test the models further, we measured tracheal PD in vivo in treated rats (reserpinized - 6.9 mV, SEM 0.7 mV, n = 7; isoproterenol-treated -10.2 mV, SEM 1.5 mV, n = 12) and found it to be no different from that of controls (-8.7 mV, SEM 0.6 mV, n = 25). The animals did, however, demonstrate a reduced gain in body weight as well as increased submaxillary gland weight, which reflected an increased mucus content in the acini. These observations suggest that although the reserpinized or isoproterenol-treated rat may be useful in the study of the pathogenesis of exocrine disturbances in disease, their use as models for the effect of the basic defect of CF in the airways may be limited.

Animals↗
PubMedDate not supplied

Impaired stimulus-evoked mucus secretion in cystic fibrosis bronchi.

Baseline and agonist-stimulated secretion of fucose, hexose, and protein (markers of mucus secretion) was investigated in vitro in 45 bronchial segments from 14 patients with cystic fibrosis (CF) (three after heart-lung transplant, the remainder < 4.5 h after autopsy), in 51 segments from 26 patients with carcinoma (24 resection, 2 after autopsy), and in 4 segments from 3 patients with bronchiectasis (resection). Basal rates of secretion of each mucus marker by CF bronchi were not significantly different from those by carcinoma bronchi bronchiectatic bronchi. However, rates of secretion of each marker in response to the cholinomimetic methacholine (10 microM; n = 11-18, depending on marker) and the beta 2-adrenoceptor agonist terbutaline (10 microM; n = 9-11) were significantly (p < .05) increased in carcinoma bronchi (by 50-117% above basal), but not in CF airways (n = 11-14). The secretory response to the sensory neuropeptide substance P (1 nM to 10 microM; n = 5-7) was also reduced in CF compared with carcinoma bronchi. Physiological and morphological data indicated that the reduced response by CF tissue could not be accounted for by inclusion of autopsy tissue in the study. These data suggest a defect in autonomic control of bronchial secretion in CF, not in the basal rate of secretion, but in its response to receptor stimulation.

Autopsy↗
PubMedDate not supplied

Amphicrine differentiation in bronchioloalveolar cell carcinoma.

We report for the first time a classical bronchioloalveolar cell carcinoma with both exocrine and endocrine differentiation (amphicrine) in the same cell. At electron microscopy the tumor cells showed a mixed type II alveolar cell/Clara cell and mucous differentiation. In addition, there were many dense-core neurosecretory granules at the base of the majority of the cells. Immunocytochemically the tumor showed positivity for surfactant and a panel of neuroendocrine antibodies, including NSE, PGP9.5, synaptophysin, and chromogranin A. The presence of neuroendocrine differentiation was not hinted at by routine histology and did not indicate a more aggressive behavior in this case since the patient is well 3 years after the resection.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMedDate not supplied

Adenocarcinoma simulating mesothelioma.

Pleural biopsy in a 45-year-old woman with a haemorrhagic pleural effusion showed malignant cells. Stains for mucin and carcinoembryonic antigen were positive and adenocarcinoma was diagnosed. Some ultrastructural features were more typical of mesothelioma.

Adenocarcinoma↗
PubMedDate not supplied

Epithelioid hemangioendothelioma of the lung.

Light and electron microscopic features of an epithelioid hemangioendothelioma of the lung in a 43-year-old woman are reported. The tumor cells stained for factor VIII-related antigen. A mass excised from the thigh 10 years earlier showed identical appearances.

Autopsy↗
PubMedDate not supplied

Pathogenesis of idiopathic interstitial pulmonary fibrosis.

The histopathology and ultrastructure of idiopathic interstitial pulmonary fibrosis is described and illustrated. There is evidence that proliferating type II pneumocytes in regenerating alveolar epithelium are implicated in the pathogenesis of this disorder.

Basement Membrane↗