Refractory ceramic fiber has been developed for industrial processes requiring materials with high thermal and mechanical stability. To evaluate the biological activity of this fiber, rat alveolar macrophages were exposed for < or = 24 h to 0-1,000 micrograms/ml of refractory ceramic fiber, crocidolite asbestos, silica (fibrogenic particles), or titanium ...

A better understanding of early cellular events following pulmonary injury may permit the identification of those patterns of response which are destined to progress to fibrosis. Interactions between inflammatory, fibroblastic and epithelial cells appear to play crucial roles in fibrogenesis. Intercellular communication may be via "messages" delivered by soluble mediators ...

Mononuclear phagocytes have the capacity to produce an array of MMPs. Several of these proteinases are capable of degrading insoluble elastin, an important component for the structural stability of the lung. Matrilysin is a low molecular weight proteinase with a broad substrate specificity produced at highest levels in in vitro ...

Systemic activation of inflammatory cascades has been implicated in the pathogenesis of the multiple organ dysfunction syndrome. To begin to determine whether dysregulation of macrophage cytokine expression after burn plays a role in organ failure, we examined tumor necrosis factor alpha bioactivity of liver and lung macrophages under two conditions: ...

Rabbit polyclonal antibodies to amino acids 346-360 of connexin 43, the 'heart' gap junction protein, were employed to immunolocalize connexin 43 gap junctions in the neonatal rat molar tooth germ. Connexin 43 appears early in the differentiation of both ectodermally derived and ectomesenchymally derived cells of the developing tooth. Connexin ...

It is generally accepted that to cause pulmonary disease, mineral fibers must be relatively long and thin but also able to remain in the lung for long periods. This "biopersistence" of fibers is limited by two main mechanisms of fiber clearance: removal by macrophages after phagocytosis and, for some fibers, ...

Cytokines are widely involved in physiologic as well as immunoinflammatory and fibrosing processes of the lung. The aim of this work was to study, by bronchoalveolar lavage, two groups of human interstitial lung diseases (ILD) with fibrosing propensity (ie, idiopathic pulmonary fibrosis [IPF], n = 10; and coal worker's pneumoconiosis ...

We are studying the development of fibrogenic lesions in the lungs of rats exposed briefly to an aerosol of chrysotile asbestos fibers. This model of asbestosis has enabled us to establish very early cellular events at the specific locations where interstitial fibrosis will develop. These sites, the first alveolar duct ...

The contribution of human alveolar macrophages (AM) from normal subjects in Cryptococcus neoformans infection was investigated. AM were able to efficiently phagocytize the fungus after opsonization, but killing activity did not occur at an effector-to-target ratio of 10:1 in a 6-h incubation since there was an inhibition of phagosome-lysosome fusion. ...

The optical histoenzymological and electronomicroscopical investigations were carried out en 90 pulmonary biopsies taken from patients under different chronic stasis conditions. To investigate macrophage-type cells we studied the reactions of acid phosphatase and non-specific esterase like enzyme markers, indicating the metabolic state activation degree of this cellular compartment. The ultrastructural ...

Local activation of macrophages may play an important role in immune complications following lung transplantation. To document such a phenomenon, we have investigated the possible changes of alveolar macrophage surface antigen expression after lung transplantation. Using immunocytofluorometry, we have analyzed the phenotype of alveolar macrophages from 41 bronchoalveolar lavage fluids ...

The Na+ transport function of alveolar epithelium represents an important mechanism for air space fluid clearance after acute lung injury. We studied the effect of endotoxin-stimulated rat alveolar macrophages on lung epithelial ion transport and permeability in vitro. Cultured rat distal lung (alveolar) epithelial monolayers incubated with both endotoxin and ...

To link ovine lentivirus infection to lung tissue damage, we studied the procoagulant response in alveolar macrophages from experimentally infected lambs and in in vitro infected alveolar macrophages. We cloned ovine tissue factor cDNA and analysed its in vitro expression by Northern blotting. Visna-maedi virus induced tissue factor mRNA. In ...

Keratinocyte growth factor (KGF) administered as a single intratracheal injection causes a prominent dose-dependent proliferation of type II alveolar epithelial cells in the lungs of adult rats. The increase in mitotically active alveolar cells histologically appears as a micropapillary epithelial cell hyperplasia after 2 d and peaks after 3 d ...

Human peripheral blood monocytes isolated by centrifugation with Mono-Poly resolving medium, and human alveolar macrophages obtained by lung lavage during fiberoscopic bronchoscopy, were cultured in RPMI containing 2% foetal calf serum. The cultures were exposed to modified human proteins: alpha-1-antitrypsin cleaved with papain, fibrinogen degradation products (fraction D) purified from ...

A distinct subpopulation of tissue-associated pulmonary macrophages (TAPM) displayed tumoricidal activity towards syngeneic and xenogeneic targets following in vitro incubation with N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP). This subpopulation, as well as, the predominant population of freely lavagable alveolar macrophages destroyed allogeneic targets following a similar incubation with either 6-0-stearoyl MDP (S-MDP) or recombinant ...

To elucidate potential mechanisms of the acute lung injury associated with endotoxemia, we evaluated the effect of intravenously administered endotoxin on the ability of alveolar macrophages isolated by bronchoalveolar lavage from normal subjects to produce inflammatory mediators. Within 1 hr of endotoxin (4 ng/kg body weight) administration, all 12 study ...

The tumoricidal activity of C3H mouse alveolar macrophages (AM) was completely abolished by 100 Gy gamma-irradiation, whereas the activities of AM of C57Black/6 (B6) and Balb/c mice were not significantly affected. The viability of AM, determined by both vital staining with crystal violet and by trypan blue exclusion, was decreased ...

The specific function of interstitial macrophages (IM) in the lung is poorly understood because of difficulties in isolating these cells in high purity or large number. In the present studies, a pure population of enzymatically isolated IM and lung macrophages obtained mechanically from the lung were compared functionally with alveolar ...

It has been shown that both calcitonin gene-related peptide (CGRP) and amylin bind weakly to calcitonin (CT) receptors in osteoclast-like cells formed in vitro and inhibit bone resorption by a cAMP-dependent mechanism. Osteoclasts are thought to be derived from cells of the monocyte macrophage lineage, in which CGRP, but not ...

The lung possesses two immune systems, one in the alveolar space, which consists primarily of alveolar macrophages, and one in the interstitium and the bronchus-associated lymphoid tissue (BALT), which comprises both nonspecific and specific components. The primary targets for invading foreign material are the alveolar macrophages. These secrete in response ...

The effect of the phosphodiesterase inhibitor isobutyl-methylxanthine (IBMX), salbutamol and sodium nitroprusside was evaluated regarding PGE2 and LTB4 release and cAMP and cGMP level in human alveolar macrophages obtained from controls and COPD patients. Basal levels per five million control- respectively COPD alveolar macrophages: cAMP 1.2 and 1.0 pmole; cGMP ...

The effects of HgCl2 on the production of leukotriene B4 (LTB4) by rabbit alveolar macrophages were investigated. Alveolar macrophages synthesized only a small amount of LTB4 when incubated in Hanks' balanced salt solution (HBSS) in the absence of stimuli or chemical reagents (0.2 +/- 0.1 ng/10(6) cells). The amount of ...

In smoking subjects with obvious emphysema, the interaction between neutrophil-derived MPO and H2O2 produced by alveolar inflammatory cells (alveolar macrophages (AM) and polymorphonuclear neutrophils (PMN)) has the ability to spontaneously inactivate, in vitro, the alpha 1 proteinase inhibitor (alpha 1PI). This inactivation can induce a desequilibrium of the protease-antiprotease balance ...

The effect of bovine respiratory syncytial virus (BRSV) upon alveolar macrophage (AM) function was investigated using an in vivo calf inoculation model. Alveolar macrophages were collected sequentially from live calves at multiple time points during the 14 day period following viral inoculation. Alveolar macrophages from bronchoalveolar lavage fluids were purified ...

Human alveolar macrophages have the capacity to degrade elastin. As an approach to define proteinases responsible for this activity, we recently cloned a murine macrophage elastase cDNA and demonstrated that it is a member of the matrix metalloproteinase gene family (Shapiro, S. D., Griffin, G. L., Gilbert, D. J., Jenkins, ...

BACKGROUND: Alveolitis in pulmonary sarcoidosis is characterised by an accumulation of highly activated macrophages and CD4+ lymphocytes in the alveolar compartment. The role of intercellular adhesion molecule 1 (ICAM-1) expression on alveolar cells has been studied in this context. METHODS: Using a sandwich ELISA technique, ICAM-1 expression on alveolar macrophages ...

Bordetella pertussis, the causative agent of whooping cough, has been shown recently to enter and survive in epithelial cells and macrophages in vitro. In the present study, we show that B. pertussis is cytotoxic for J774A.1 cells, a monocyte-macrophage cell line, and for murine alveolar macrophages. We demonstrate that cell ...

The relative activation of eicosanoid production which results from the exposure of the alveolar macrophage (AM) to mineral dusts is thought to be a key factor in the pathophysiology of occupational lung disease. We compared in vitro basal and silica-stimulated production of prostaglandin E2 (PGE2) and thromboxane A2 (TXA2) by ...

Exposure of rats to hyperoxia (100% oxygen for 64 h) resulted in striking alterations in the properties of samples obtained by bronchoalveolar lavage. The yield of neutrophils, lymphocytes, and red blood cells was increased, while the number of harvested alveolar macrophages decreased. The acellular lavage fluid level of protein was ...

A new class of long-acting beta 2-adrenoceptor agonists has been studied in the last few years. Apparently, they display an important anti-inflammatory activity with an inhibition of different cellular functions. This study was carried out to compare a long-acting beta 2-agonist, formoterol, with a conventional short-acting one, salbutamol, on the ...

Alveolar macrophages (AMs) from patients with interstitial lung diseases, such as sarcoidosis and idiopathic pulmonary fibrosis, suppress the phytohaemagglutinin (PHA) stimulation of autologous peripheral lymphocytes. The aim of this study was to determine whether the suppressive effect of alveolar macrophages of patients with interstitial lung disease is due, not only ...

The purpose of these studies was to examine the effects of in vivo and in vitro recombinant IL-3 treatment on alveolar macrophage and monocyte activities associated with antitumor and antimicrobial properties. Alveolar macrophages and blood monocytes from 6 patients receiving IL-3 (125-500 micrograms/m2/day) subcutaneously were isolated before therapy and at ...

Pneumocystis carinii is an opportunistic organism that causes severe lung injury in immunocompromised hosts. Macrophage responses to P. carinii are poorly defined. Arachidonic acid (AA) and its metabolites are potent mediators of inflammation and have been implicated in host response to microorganisms. We therefore examined the production of eicosanoids from ...

Impairment of cell-mediated immunity is both a common manifestation of critical illness and a potential cause of increased infectious morbidity and mortality. The mechanisms responsible for alterations in systemic immune regulation are incompletely understood; however, monocytes and fixed tissue macrophages appear to play a central role. We have previously shown ...

Recruitment and activation of mononuclear phagocytes are potentially critical regulatory events for control of pulmonary inflammation. Located at the boundary between the alveolar airspace and the interstitium, alveolar epithelial cells are ideally situated to regulate the recruitment and activation of mononuclear phagocytes through the production of cytokines in response to ...

The chemiluminescence of peripheral blood monocytes and alveolar macrophages was determined in the presence of luminol and lucigenin, either before or after the cell adherence to the luminometer curvettes. In the case of monocytes, cell adherence induces an increase of luminol-dependent chemiluminescence and has almost no effect on the lucigenin-dependent ...

Alcohol consumption is known to predispose the host to more frequent and severe bacterial infections, suggesting that alcohol compromises the normal immune function of the lung. The pulmonary alveolar macrophage is the resident host defense cell in the lung and forms the first line of defense against invading microorganisms. One ...

This study addresses the hypothesis that silica-activated alveolar macrophages could release soluble factors stimulating type II cell proliferation. Macrophages from control sheep were exposed or not in vitro to silica, aluminum-treated silica (Si-Al), or titanium dioxide (TiO2). In addition, macrophages from a model of chromic silica-exposed sheep were studied. Supernatants ...

The in vitro production of PGE2 and TxA2, measured as TxB2, and the antibody-dependent cellular cytotoxicity (ADCC) as well as spontaneous cellular cytotoxicity (SCC) displayed by hepatic, peritoneal, splenic, and alveolar macrophages from 12 rats was determined and compared. Kupffer cells, the fixed macrophages of the liver, were the most ...

This paper investigates the effector mechanisms of immune clearance in the lungs of rats immunized against mucoid Pseudomonas aeruginosa. After the gut-associated lymphoid tissue was primed and after a subsequent pulmonary challenge with live bacteria, significantly accelerated bacterial clearances from the lung and raised levels of anti-P. aeruginosa antibodies in ...

In this study we evaluated the effect of cigarette smoke on the activation of alveolar macrophages of the rat lungs exposed to an episode of acute passive cigarette smoking. Our experiments were carried out in rats that, after undergoing smoking (3 cigarettes within 1 h) showed a COHb increase of ...

Amiodarone can cause pulmonary toxicity along with an increase in phospholipid in macrophages, lymphocytes, and other cell types. Phospholipid accumulates because amiodarone inhibits the lysosomal phospholipases A1 and A2. Since a wide array of cells are affected by amiodarone and because amiodarone might inhibit other phospholipases, we postulated that cellular ...

The effect of filtration through two layers of cotton gauze on the cellular composition of bronchoalveolar lavage (BAL) fluid was studied in 25 patients with pulmonary disease. There was no significant difference between median total cell count in unfiltered and filtered BAL (P = 0.73) or in the distribution of ...

The production of superoxide anions (superoxide) from alveolar macrophages stimulated or not with opsonized zymosan was investigated in the mouse after acute oral administration of alcohol (6.5 g/kg). Superoxide production was assayed using a nitroblue tetrazolium (NBT) reduction and chemiluminescence assay. In the absence of opsonized zymosan, superoxide concentration was ...

Alveolar macrophages have recently been postulated as being involved in the aetiology of adult respiratory distress syndrome (ARDS). To evaluate their role, basal cyclic AMP levels and responsiveness of adenylyl cyclase alveolar macrophages were determined at four intermediate stages of developing respiratory distress in piglets using a protocol with repeated ...

It has been shown in previous studies that alveolar macrophages incubated with bleomycin in vitro for 2 to 18 hours secrete monocyte chemotactic factors and fibroblast growth factors (MDGF). The purpose of the current experiments was to determine if alveolar macrophages similarly stimulated with bleomycin would continue to secrete these ...

The mechanisms by which cigarette smoking lead to bronchopulmonary diseases are incompletely understood. The most characteristic lesion is a chronic macrophage-alveolitis accompanied by slight fibrosis and emphysema. The macrophages contain a ceroid-like granular autofluorescent pigment in their lysosomes. Using immunohistochemical methods, open lung-, transbronchial biopsies and cells obtained by broncho-alveolar ...

Tetrandrine is a bisbenzylisoquinoline alkaloid which has been shown to exhibit antifibrotic activity against silicosis. Tetrandrine is characterized by its strong binding to alveolar macrophages and inhibition of particle-induced respiratory burst activity in these phagocytes. In contrast, tubocurine and tubocurarine are structurally similar to tetrandrine but exhibit little effect on ...

Beta-2-integrins belong to a family of leukocyte surface glycoproteins that are essential for immune functions of bronchoalveolar cells. The expression of three alpha chains designed as CD11a, CD11b, CD11c, a common beta chain CD18, and of a ligand for several integrins CD54 (ICAM-1) was studied on alveolar macrophages of patients ...