Eosinophilic lung reaction to aluminium and hard metal.

A nonsmoker drill polisher with interstitial lung disease is presented. The environmental exposure was mainly to aluminum oxide, aluminum silicate, and hard metals. Bronchoalveolar lavage revealed high eosinophilia, and transbronchial biopsy specimen disclosed interstitial pneumonia with giant cell infiltrates and peribronchiolar accumulation of macrophages laden with opaque dust. Mineralogic studies done from the tissue revealed a high concentration of exogenous particles that were identified as hard metals and aluminum silicate. These findings are compatible with hard metal pneumoconiosis.

Alveolar haemorrhage with pleural effusion as a manifestation of epithelioid haemangioendothelioma.

A 22 year old male was admitted with haemoptysis. A chest X-ray showed bilateral confluent alveolar infiltrates. Bronchoscopy revealed blood oozing from all bronchopulmonary segments. Open lung biopsy disclosed bilateral effusions and large necrotizing nodules with pleural adhesions. Histological examination showed tumour cells, which were negative to epithelial and embryogenic markers but positive to factor VIII. This confirmed the diagnosis of an epithelioid haemangioendothelioma. This rare tumour, usually has an indolent course, whereas in our case it was complicated by alveolar and intrapleural bleeding.

Quinacrine inhibits oxygen radicals release from human alveolar macrophages.

We examined the effect of quinacrine, an anti-malarial drug which inhibits phospholipase A2, on phorbol myristate acetate (PMA) stimulated alveolar macrophage oxygen radical secretion. This drug suppressed 30% of radicals release, which was 70% of the amount inhibited by superoxide dismutase, a specific inhibitor of oxygen radicals. In addition, this reduction was at the same magnitude as dexamethasone. This and previous results on other inflammatory cells support the assumption that quinacrine may have a beneficial effect on bronchial asthma.

Class II antigens of the major histocompatibility complex are increased in lungs of bleomycin-treated rats.

The expression of class II molecules (Ia) of the major histocompatibility complex by isolated alveolar macrophages (AM) and alveolar type II cells from the lungs of rats with bleomycin-induced pulmonary fibrosis was examined. The percentage of Ia-positive AM and type II cells from rats treated with bleomycin as detected by flow cytometry was increased three times and two times, respectively, over the values obtained from control rats. The relative density of Ia expression, determined with a radioimmunoassay technique, showed a 50% increase in Ia density on AM and a 35% increase on type II cells. Recombinant interferon-gamma increased the expression of Ia on type II cells in vitro by 35% to the level obtained on type II cells in bleomycin-induced lung disease. We conclude that the increase of Ia expression on cells of the immune system and on pulmonary epithelial cells may have an important role in the initiation and/or amplification of inflammatory reactions in the lung and may contribute to the development of pulmonary fibrosis.

An apparatus for the measurement of lung volume and compliance in mice.

Pressure-volume (P-V) curves and total lung capacity (TLC) were measured in excised lung of mice using a water manometer and a closed system in which the humidity and temperature were controlled. In pathogen-free mice there are no significant differences in elastic properties of these lungs in relation to their age. The measured TLC in those normal mice was approximately 2.9 ml. This relatively simple apparatus which allows one to make sensitive and accurate measurements of pulmonary function in mice and other small animals.

Anti-Ia antibodies inhibit the spontaneous secretion of IL-1 from silicotic rat alveolar macrophages.

Class II antigens of the major histocompatibility complex (Ia) are important components in the investigation of cell-mediated immune responses. Several reports have indicated that anti-Ia monoclonal antibodies suppress disease development in animal models. In this paper, the expression of Ia and the effect of anti-Ia on IL-1 secretion from alveolar macrophages (AM) from silica-treated rats was examined. The results obtained showed that 45% of silicotic AM, but only 5% of AM from normal control rats, express Ia antigen. Anti-Ia treatment of silicotic AM reduced IL-1 secretion by 55%. We conclude that anti-Ia immune suppression may involve the inhibition of IL-1 secretion.

Increased expression of class II antigens of the major histocompatibility complex on alveolar macrophages and alveolar type II cells and interleukin-1 (IL-1) secretion from alveolar macrophages in an animal model of silicosis.

Silicosis is a chronic progressive granulomatous and fibrotic lung disease caused by inhaled silica. Although the causative agent is known, the pathogenesis, especially the immunologic response, is not well understood. We examined two important components of cell-mediated immune responses in the lungs of rats with silica-induced lung disease, i.e., class II (Ia) antigen expression and IL-1 production. The relative density of Ia was examined on isolated alveolar macrophages and type II cells with a solid-phase cellular radioimmunoassay and the percent of Ia positive cells was determined by an indirect immunofluorescent technique. There was a three-fold increase of Ia expression on the alveolar macrophages and nearly a two-fold increase on type II cells from rats with silicosis compared to normal rats. The percent of alveolar type II cells positive for Ia increased by 20%, and the alveolar macrophages increased by 40%. IL-1 in supernatants from cultured alveolar macrophage was measured by the amount of DNA synthesis in an IL-1 dependent cell line (D10). A six-fold increase in IL-1 secretion was noted in macrophage supernatants derived from silica-treated animals. We conclude that in this animal model of silicosis, a local amplification of cell-mediated immune responses may be instrumental in the pathogenesis.

Lymphocyte populations in lung tissue, bronchoalveolar lavage fluid, and peripheral blood in rats at various times during the development of silicosis.

Inflammatory cells and lymphocyte populations were examined in the bronchoalveolar lavage (BAL) fluid, lung tissues, and peripheral blood from rats at various times after the intratracheal instillation of silica. In lavage fluid, there was a rapid initial increase in the percentage and number of polymorphonuclear leukocytes (PMN), which slowly decreased during the course of the experiment. In addition, compared to controls, there was an increased number and percentage of lymphocytes throughout the 75 days of the experiment. The lymphocytic populations, which were determined by an indirect immunofluorescence method with monoclonal antibodies to lymphocyte surface markers, showed a predominance of the T-helper phenotype from Day 14 through the end of the experiment (Day 75). The number of PMNs obtained from collagenase digest of the lung was increased over control levels up to Day 7 after silica administration and remained at a relatively constant level until Day 14, after which time they decreased slightly in number. The total number of lymphocytes peaked on Day 14, with cells of the T-helper phenotype predominating after this time. In the peripheral blood, T-helper cells from silicotic rats were significantly increased over control rats on Days 7 and 14 but returned to normal control values after this time. The lymphocyte subsets in the BAL, but not in the peripheral blood, more closely reflect the lymphocyte patterns in the lung. The results of these experiments suggest that T-helper cells may play an important role in the inflammatory-fibrotic events in the lungs of rats with silicosis.

Class II molecules on rat alveolar type II epithelial cells.

Class II (Ia) molecules of the major histocompatibility complex are important in the presentation of antigen to T cells and in the regulation of the immune response. Recent studies have suggested that many epithelial cell types can express class II molecules. We examined rat alveolar type II epithelial cells, a cell which can synthesize and secrete pulmonary surface-active material, for the expression of class II antigens. Using an indirect immunofluorescent technique with a mouse anti-rat class II monoclonal antibody (OX-4), the majority of type II cells isolated from pathogen-free Sprague-Dawley rats expressed Ia antigens as determined by fluorescent microscopy and cell sorter analysis. In culture, the Ia expression was lost from type II cells. The addition of recombinant interferon-gamma to cultures of type II cells induced the expression of class II antigens. These findings suggest that class II antigen expression on type II cells may have relevance to immune responses occurring in the lung.

Elastic properties of the excised lungs of NZB/W mice and their correlation with histopathologic changes.

Lung volume and the pressure-volume (PV) relationships of the lung were determined in excised lungs of an animal model of human systemic lupus erythematosus, which develops in NZB/W mice, and correlated with histopathologic changes. In young, 4-month-old NZB/W mice, and in nonautoimmune BALB/c mice at any age, there were minimal histologic changes or alterations in lung function. The NZB/W mice developed histologic changes with aging. Perivascular, peribronchial, and interstitial changes developed and were associated with a significant reduction in total lung capacity as well as changes in the pressure-volume characteristics of the lung, which are compatible with a restrictive process.

Inhibition of induced acute lung edema by a novel protein kinase C inhibitor.

The effect of the protein kinase C enzyme inhibitor H-7 on the noncardiogenic lung edema induced by phorbol myristate acetate (PMA) in mice was examined. Lung edema was assessed by measurement of 125I-labeled albumin leak into the lung. The results showed that pretreatment of mice with H-7 nearly prevents the albumin leak induced by PMA, whereas post-PMA treatment with H-7 had less of an effect on the albumin leak, although it was still significant.