SCID-Hu mouse as a model for human lung HIV-1 infection

HIV induces a multi-organ infection with a dual tropism for both lymphocytes and monocytes/macrophages. The lung is a target both for HIV infection and HIV-related opportunistic infections. The SCID mouse has provided the opportunity to develop a small animal model for HIV infection. However, HIV-1 infection of the human fetal thymus and liver (SCID Liv/Thy) implanted in these mice occurred only after direct intraimplant injection of HIV-1 and the resultant HIV-1 infection was restricted to the human thymus. Here we report that human foetal lung can develop in SCID Liv/Thy mice resulting in the development of normal human alveolar and bronchiolar lung compartments which can be productively infected with cell-free HIV-1 virus, leading to a systemic and bifocal infection. This SCID-Hu model should be useful for studying AIDS physiopathology, human viruses with lung tropism and for helping to define gene therapy protocols in lung human cells in vivo.

[Pulmonary macrophages during combined exposure to ionizing radiation and nitrogen oxides]

The dynamics of cellular population of mice alveolar macrophages has been studied under separate and combined effects of ionizing radiation and nitrogen oxides. It has been shown that the combined effect exceeds significantly the sum of separate effects of the above factors with equal dose and concentration levels.

A study on cellular reactions and fibrogenic effects of mineral dusts

In vivo cytotoxicity including cellular metabolic activity, lysozyme content and total protein content in rat bronchoalveolar lavage, capacity of interleukin-1 released from rat pulmonary cells and fibrogenic effects evaluated from rat lung dry weight, collagen content of the whole lung and pathological grading induced by mineral dust were assayed. The results showed that: (1) The relationship among in vivo cytotoxicity, interleukin-1 release, fibrogenic effects on the lung induced by mineral dusts correlated well with the free SiO2 content in mineral dusts in most (but not all) cases; (2) The biological harmful effects of mixed dusts were not simply the additive effect of single dust. In the group of WO3-SiO2 mixture, the fibrogenicity was mainly due to SiO2, tungsten trioxide (WO3) showed neither fibrogenic effect, nor significant potentiality to enhance SiO2 fibrogenicity, while in the group of SnO2-SiO2, SnO2 was suppressive to the effect of SiO2, although the contents of SiO2 in the two mixed dusts were similar.

Formaldehyde-free collagen glue in experimental lung gluing

Because of the well-known limitations of the adhesive strength of fibrin glue, it is imperative to develop a stronger glue with acceptable biocompatibility. This was accomplished by removing the formaldehyde component from gelatin-resorcinol-formaldehyde glue and replacing it by two less toxic aldehydes--pentanedial and ethanedial. To evaluate the adhesive strength of this new glue, GR-DIAL, lung incisions in rabbit hybrids were glued together. Each group (n = 5) was examined histologically after 2 days and 1, 2, and 4 weeks. The glue disintegrated gradually with good bioresorption when the incision was closed with a thin layer of glue. The healing process was favorable, indicating good biocompatibility. Therefore, GR-DIAL glue is capable of enhancing the use of surgical glues in the field of thoracic surgery by enabling surgeons to close larger parenchymal lesions than with fibrin glue.

Impaired alveolar macrophage accessory cell function and reduced incidence of lymphocytic alveolitis in HIV-infected patients who smoke

OBJECTIVE

To determine the effects of smoking on alveolar macrophage (AM) accessory cell (AC) function and the incidence of lymphocytic alveolitis in asymptomatic HIV-infected individuals.

METHODS

AM AC function in smoking and nonsmoking HIV-positive volunteers was measured in concanavalin A and pokeweed mitogen assays. Mitogen-induced AM-T-cell adherence was determined. AM cytokine secretion was analyzed by interleukin (IL)-6 bioassay and IL-1 enzyme-linked immunosorbent assay (ELISA). The incidence of lymphocytic alveolitis in both groups was determined.

RESULTS

AM from smokers were significantly poorer AC than AM from nonsmokers. Though AM-T-cell adherence was unaffected by smoking, IL-1 and IL-6 secretion was significantly impaired. Lymphocytic alveolitis was significantly less common in HIV-infected smokers.

CONCLUSION

Smoking reduces AM AC function in HIV-infected individuals, probably by impairing secretion of cytokines important in T-cell proliferation. This may explain the decreased incidence of lymphocytic alveolitis in HIV-infected people who smoke.

Early diagnosis of fat embolism syndrome by automated image analysis of alveolar macrophages

To evaluate the value of automated semiquantitative analysis of fat within alveolar macrophages as an early diagnostic tool for fat embolism syndrome (FES), we investigated 3 patients with respiratory failure following long-bone fractures. The mean area of fat droplets per alveolar macrophage was determined in pixels and, additionally, the percentage of the evaluated areas was calculated. In 2 patients, the diagnosis of FES could be established as early as 24 hr after trauma. Both patients showed an increase in the area of fat per alveolar macrophage (pixels: 851, 1069) as well as in the percentage of fat area per alveolar macrophage area (40.04%, 52.73%), whereas the analysis of the bronchoalveolar lavage (BAL) specimens of a third patient, who later recovered without appearance of clinical signs of FES, revealed only minimal fat content (pixels: 82; 3.82%). Automated semiquantitative analysis of fat within alveolar macrophages may be helpful in the early diagnosis of FES.

Abnormal pulmonary macrophages in lysinuric protein intolerance. Ultrastructural, morphometric, and x-ray microanalytic study

Pediatric patients with lysinuric protein intolerance are predisposed to develop alveolar hemorrhage and pulmonary alveolar proteinosis. We evaluated the ultrastructural features of pulmonary alveolar proteinosis and the potential abnormality of pulmonary macrophages in lysinuric protein intolerance. Lung tissue specimens obtained at autopsy were examined by transmission electron microscopy. Pulmonary macrophages from bronchoalveolar lavages were studied by electron microscopy, morphometry, and x-ray microanalysis and compared with control cells. The macrophages of patients with lysinuric protein intolerance contained significantly more multilamellar structures than did control cells and showed electron-dense material identified to contain excess iron. The predisposition to develop alveolar proteinosis and the abnormal ultrastructure of pulmonary macrophages suggest altered phospholipid metabolism in patients with lysinuric protein intolerance. The marked intramacrophageal accumulations of iron might indicate altered iron metabolism or subclinical hemorrhages in lung tissue.

Pulmonary inflammation induced by repeated inhalations of beta(1,3)-D-glucan and endotoxin

In an animal model of hypersensitivity pneumonitis (HP) guinea-pigs were exposed for 5 weeks to an aerosol of bacterial endotoxin, beta(1,3)-D-glucan (curdlan) or a combination. Exposure to endotoxin or curdlan showed only small changes in inflammatory cells in airways or the lung wall, histologically or in terms of enzyme secretion from alveolar macrophages. When the two agents were given together, a histology resembling HP was seen with alveolar infiltrates and early granulomas. Inflammatory cells in airways were increased and enzyme production of macrophages was changed, suggesting an effect of curdlan on the inflammatory regulating capacity of airway macrophages. The results suggest that interference with macrophage function and inflammation are important components in the development of HP.

Species differences in lectin binding to pulmonary cells: Soybean agglutinin (SBA) as a marker of type I alveolar epithelial cells and alveolar macrophages in mini pigs

We compared lectin staining patterns in rat and mini pig tissues of normal and fibrotic (irradiation-induced) lungs. Two lectins were studied: Dolichos biflorus (DBA) and Soybean (SBA). Both lectins strongly stained a subpopulation of alveolar macrophages. In the rat, DBA positive macrophages were a subpopulation of the SBA binding cells. In mini pig lungs, a further specific binding of DBA and SBA was observed: DBA reacted with endothelia, and SBA stained the alveolar type I cells. Double immunofluorescence experiments using a type II cell-specific cytokeratin antibody confirmed the selective reactivity of SBA with type I cells, which was also present in fibrotic areas with epithelial cell proliferation.

Cytology of bronchoalveolar lavage in some rare pulmonary disorders: pulmonary alveolar proteinosis and amiodarone pulmonary toxicity

Cytological patterns of bronchoalveolar lavage (BAL) in pulmonary alveolar proteinosis (PAP) and amiodarone pulmonary toxicity (APT) are presented together with light and electron microscopy (EM). The differential cell count of BAL in both diseases is similar in that alveolar macrophages predominate. However, the cytology of PAP is characterized by scanty macrophages and alveolar epithelial cells in abundant periodic acid-Schiff (PAS)-positive extracellular material. The gross appearance of the BAL fluid is therefore opaque. In contrast, the cytology of APT is characterized by foamy alveolar macrophages with numerous lamellar bodies in their cytoplasm, and the BAL fluid is clear.

Lymphocytic alveolitis in a crematorium worker

An asymptomatic cremator was found incidentally to have lymphocytic alveolitis by bronchoalveolar lavage, and the basis for this finding was investigated. No known causes of lymphocyte alveolitis including sarcoidosis, hypersensitivity pneumonitis, berylliosis, tuberculosis, or fungal diseases of the lung were found. By exclusion, therefore, exposure to formaldehyde and/or to compounds in the residual ash likely were etiologic in the development of the lymphocytic alveolitis.

Pulmonary inflammatory cell response to sustained endotoxin administration

We have developed a model of human sepsis in sheep. Twenty-four hours after continuous infusion of Escherichia coli endotoxin (lipopolysaccharide) (10 ng.kg-1.min-1) was begun, pulmonary transvascular fluid flux was almost five times the baseline values, cardiac output was nearly doubled, and mean arterial pressure was reduced by approximately 20 mmHg. At this time, the animals were killed and their lungs were fixed by endotracheal installation of 2.5% glutaraldehyde at 25 cmH2O pressure. Morphometry was performed by point counting, and data were expressed as relative volume density. Pulmonary edema and congestion were observed in sheep receiving lipopolysaccharide, whereas sham controls appeared normal. There was an increase in interstitial volume density. There was a significant increase (P < 0.01) in volume density of the pulmonary intravasculature (180%), interstitial macrophages (270%), and mast cells (240%). The volume densities of intravascular and interstitial polymorphonuclear neutrophils also showed a small insignificant increase.

Meconium-induced lung injury mediated by activation of alveolar macrophages

To clarify the mechanism of meconium-induced cellular injury, we examined the effect of meconium on the alveolar macrophages (AM) and bronchial epithelial cells (AK-D). Meconium obtained from healthy newborns was added to culture medium of AM and/or AK-D, which were cultured for 1 hour. Superoxide anion production of AM and the expression of intercellular adhesion molecule-1 (ICAM-1) on AK-D stimulated by meconium or oxygen radicals were determined. As a result, superoxide anion production of AM significantly increased when AM was cultured with meconium. Expression of ICAM-1 on AK-D appeared when AK-D was stimulated by hydroxyl radical but did not when AK-D was cultured with meconium. These results suggest that meconium-induced lung injury may occur through an activation of alveolar macrophages and the macrophage-epithelial cell axis may be important for the pathogenesis of meconium aspiration syndrome.

Accumulation of alveolar macrophages induced by inhalation exposure of coal fly ash in golden hamster lungs

To investigate the possible mechanisms of the accumulation of particle-laden alveolar macrophages (AMs) in alveoli, male golden hamsters were exposed to coal fly ash (FA) at the concentration of 0 or 2 mg/m3 for 6 months (20 hr/day, 7 days/week) in the first series of experiments, and at 0, 1, 2, or 20 mg/m3 of FA for 3 months in the subsequent experiments. Particle-laden AMs accumulated dose- and time-dependently in alveoli. In the lungs of 1 and 2 mg/m3-exposed groups. AMs first appeared in a cluster in alveoli at the alveolar-bronchiole junctions proximal to the lobar bronchus. Agglomerated AMs in these regions were generally larger in size and ingested more particles than those in the peripheral regions. These results indicate that the accumulation of AMs is closely related to the amount of particles deposited in alveoli and that ingested by AMs. Histochemical analysis revealed that AMs with small amount of particles showed the positive activity of acid phosphatase. On the other hand, heavily particle-laden AMs showed no such activity. Scanning electron microscopic observations revealed the time-related formation of small blebs and loss of surface features on the cell surface of AMs. These results suggest that the accumulation of particle-laden AMs might be caused by the decrease and/or loss of their activities, especially their mobility during migration toward terminal bronchioles from alveoli, due to the increase of ingested particles in parallel with the prolongation of exposure time.

Asymptomatic pulmonary involvement in 2 children with Niemann-Pick disease type B

We present 2 cases of children with Niemann-Pick disease type B, and surprisingly with reticular lung infiltrations, although otherwise healthy in terms of pulmonary manifestation. Finding such reticular infiltrations should lead one to think of the possibility of metabolic storage disease.

Epidermal growth factor-like activity in bronchoalveolar lavage fluid in experimental silicosis

We investigated whether development of pulmonary fibrosis following inhalational exposure of mice to silica (quartz) dust was accompanied by enhanced secretion of activity resembling epidermal growth factor (EGF). Mitogenic activity for pulmonary fibroblasts was assessed in bronchoalveolar lavage fluid (BALF) using a serum-free bioassay. Activity in BALF from mice exposed to nonfibrogenic titanium dioxide dust was comparable to that in BALF from normal animals. In contrast, mitogenic activity was significantly increased at 6 and 12 weeks after inhalation of silica particles, coinciding with the appearance of collagenised lesions in the lung. BALF from mice exposed to silica 6 weeks previously had significantly higher concentrations of growth factor(s) able to bind to EGF receptors on pulmonary fibroblasts. In parallel, macrophages within inflammatory lesions in the airspaces acquired immunoreactivity for EGF. The presence of an increased concentration of EGF-like growth factor(s) in BALF might constitute a marker of particle-induced pulmonary fibrosis.

Porcine reproductive and respiratory syndrome virus: morphological, biochemical and serological characteristics of Quebec isolates associated with acute and chronic outbreaks of porcine reproductive and respiratory syndrome

Cytolytic and noncytolytic strains of the porcine reproductive and respiratory syndrome virus (PRRSV) were isolated in primary cultures of porcine alveolar macrophages (PAM) from lung homogenates of stillborn fetuses or blood samples of dyspneic piglets collected from Quebec pig farms having experienced acute or chronic outbreaks of PRRS. Serological identification of the virus was confirmed by indirect immunofluorescence and indirect protein A-gold immunoelectron microscopy using reference antiserum prepared from experimentally-infected specific pathogen free (SPF) piglets and monoclonal antibodies (MoAbs) directed against the p15 nucleocapsid (N) protein of the reference ATCC-VR2332 isolate. Intracytoplasmic enveloped viral particles that tended to accumulate into cytoplasmic vesicles were observed in the infected PAM; no budding was demonstrated at the level of the cytoplasmic membrane. The extracellular virions appeared as pleomorphic but mostly spherical enveloped particles, 50-72 nm in diameter (averaged diameter of 50 particles was 58.3 nm), with an isometric core about 25-30 nm. Buoyant density of the virus in CsCL density gradients was estimated to 1.18-1.20 g/mL. No hemagglutinating activity was demonstrated. Analysis of semipurified virions of isolate IAF-exp91 by radioimmunoprecipitation (RIPA) and Western immunoblotting experiments, using reference rabbit and porcine hyperimmune sera, revealed four major viral proteins, a predominant 15 kD N protein and three other proteins with predicted M(r_ of 19, 26 and 42 kD. Progeny viral particles produced in PRRSV-infected PAM in the presence of tunicamycin lacked the 42 kD protein, thus confirming its N-glycosylated nature. Immunoprecipitation experiments using the anti-ATCC-VR2332 MoAbs confirmed the close antigenic relationships between Quebec and American reference isolates of PRRSV.

Immunohistochemical localization of transforming growth factor-beta 1 in the nonnecrotizing granulomas of pulmonary sarcoidosis

Sarcoidosis is a chronic inflammatory disease of unknown cause characterized by the formation of nonnecrotizing granulomas in affected tissues, most notably the lungs. Granuloma healing may result in pulmonary fibrosis and respiratory impairment in some patients. Transforming growth factor-beta 1 (TGF-beta 1) is a potent cytokine that promotes fibrosis by enhancing the synthesis of extracellular matrix components, including fibronectin and the alpha 5 beta 1 fibronectin receptor. The role of TGF-beta 1 in promoting lung fibrosis in the setting of pulmonary sarcoidosis has not yet been investigated. Accordingly, we determined the extent and distribution of TGF-beta 1 in lung tissue obtained from seven patients with clinical and histologic features of pulmonary sarcoidosis. The tissue distributions of TGF-beta 1, the TGF-beta 1 binding proteoglycan decorin, fibronectin, and the alpha 5 beta 1 fibronectin receptor were assessed immunohistochemically. In all cases, the epithelioid histiocytes comprising nonnecrotizing granulomas of pulmonary sarcoidosis contained abundant TGF-beta 1. We further demonstrated decorin, fibronectin, and the alpha 5 beta 1 fibronectin receptor within nonnecrotizing granulomas and in the fibrous tissue surrounding the lesions. TGF-beta 1 staining was also observed in bronchiolar epithelial cells, hyperplastic Type II pneumocytes, and occasional alveolar macrophages. This study demonstrates enhanced tissue localization of TGF-beta 1 and related extracellular matrix proteins associated with the nonnecrotizing granulomas of pulmonary sarcoidosis. Through its actions on matrix protein synthesis, TGF-beta 1 may modulate the fibrotic repair process accompanying granuloma healing in sarcoidosis.

Airway macrophages from patients with asthma do not proliferate

BACKGROUND

Macrophages are involved in asthma, but their pulmonary turnover is unknown. We compared the ability of bronchoalveolar lavage (BAL) and bronchial macrophages to proliferate in normal subjects and patients with asthma.

METHODS

BAL cells from eight patients with asthma and eight normal volunteers were separated with a discontinuous Percoll gradient (Pharmacia Fine Chemicals, Uppsala, Sweden). In a first experiment, nuclei of each alveolar macrophage (AM) fraction, stained with propidium iodide, were analyzed for DNA content with a flow cytometer, and the proportions of cells in the G0/G1, S, and G2 + M phases were determined. In a second experiment, expression of Ki-67-related antigen was sought on AMs by immunocytochemistry. Macrophages from 10 patients with asthma and 10 normal volunteers were studied in biopsy specimens by means of immunohistochemistry with a panmacrophage monoclonal antibody (HAM-56) and a monoclonal antibody against proliferating cell nuclear antigen.

RESULTS

The proportions of BAL AMs in the different phases of the cell cycle were similar in normal subjects and patients with asthma for all fractions, and the percentage of cells in S and G2 +/- M phases ranged from 7.3% to 11.3%. Under 1% of BAL AMs expressed Ki-67-related antigen. None of the macrophages present in the biopsy specimens expressed proliferating cell nuclear antigen.

CONCLUSIONS

This study does not indicate that an important source of airway macrophages is local proliferation.

Effects of parainfluenza type 3 virus on guinea pig pulmonary alveolar macrophage functions in vitro

The influence of parainfluenza type 3 (PI-3) virus on the release of inflammatory mediators by guinea pig pulmonary alveolar macrophages (PAMs) was investigated in vitro. Direct application of PI-3 virus dose-dependently stimulated the generation of chemiluminescence by PAMs and induced aggregation of PAMs. No significant effects of PI-3 virus on the release of linoleic acid metabolites by PAMs were detected. However, an increased release of the arachidonic acid metabolite thromboxane B2 (TxB2) was observed when PAMs were stimulated with PI-3 virus. PAMs were also cultured for 2 h or 18 h in the presence of PI-3 virus or control medium. The production of reactive oxygen species and the release of fatty acid metabolites by these PAMs were determined upon stimulation with opsonized zymosan particles or phorbol myristate acetate. The amounts of hydrogen peroxide and superoxide produced did not differ between virus- and control medium-incubated PAMs. However, the PI-3 virus-treated PAMs generated twice as much chemiluminescence when compared to PAMs incubated with control medium. The 2-h incubation period with PI-3 virus also resulted in a decreased release of TxB2 from the PAMs upon zymosan stimulation. The changes in the production of reactive oxygen species and the release of TxB2 by PAMs could account for damage to the airways and bronchial hyperresponsiveness often seen after viral infection.

Alveolar macrophages and the diagnosis of drowning

In the present study, we examined the number of alveolar macrophages in lung tissue from 17 cases of fresh water drowning, 22 cases of acute death and 6 cases of lung emphysema. When counting only the number of alveolar macrophages per alveolus without consideration of the alveolar size we found no relevant differences between the groups investigated. To exclude any influence of the alveolar size on the results the surface density of the alveolar macrophages and interstitial tissue was estimated and compared in the different groups. In cases of drowning, the lungs showed significantly lower values in both categories. The ratio of 'alveolar macrophages/interstitial tissue' was also reduced in cases of drowning in comparison to the other groups, however, without significant differences. These morphometrical results characterizing the 'emphysema aquosum' with almost 'empty' and dilated alveoli could be explained by a wash-out effect of the drowning fluid leading to a partial removal of the macrophages from the alveoli. This hypothesis was confirmed by the detection of alveolar macrophages in the drowning froth by immunohistochemical analysis. Even though alveolar macrophages were unambiguously identified in advanced putrefied lungs in HE-stained sections as well as by immunohistochemical staining, an estimation of the number of these cells cannot provide further information for the diagnosis of drowning in putrefied corpses due to the autolytic destruction of the lung architecture providing no reliable values.

Increased expression of adhesion molecules (ICAM-1 and LFA-1) on alveolar macrophages from asthmatic patients

In the airways inflammation observed in asthma, activated macrophages are present in increased numbers. Adhesion molecules are required for the cell:cell contacts between leukocytes and endothelial cells or other leukocytes, and they are induced by inflammatory stimuli. We studied the expression of two adhesion molecules (ICAM-1 and LFA-1) on alveolar macrophages recovered by bronchoalveolar lavage from 11 normal subjects and 13 asthmatic patients by using immunocytochemistry. Two specific monoclonal antibodies were used, and the reaction was revealed by the alkaline phosphatase-antialkaline phosphatase (APAAP) method. The percentage of cells expressing ICAM-1 or LFA-1 was significantly increased in asthmatic patients, as compared with normal subjects (P < 0.001 and P < 0.002, respectively; Mann-Whitney U test), and there was a significant correlation with the percentage of cells expressing both markers in asthma (P < 0.03, Spearman rank test). This study highlights the importance of macrophages in the inflammation of asthma and suggests that macrophage interactions with other cells play a role in this inflammation.

[Double infection of the lung with Pneumocystis carinii and Cryptococcus neoformans in an AIDS patient]

A 25-year old HIV-1-positive hemophiliac was admitted with fever, cough, exertional dyspnea and pleuritic chest pain. Chest x-ray showed diffuse bilateral infiltrates with a left sided nodular consolidation. Pneumocystis-carinii-pneumonia was suspected and diagnosed by broncho-alveolar lavage. With therapy the diffuse infiltrates improved, but the nodule and the symptoms failed to resolve. A fine-needle aspiration of the nodule revealed concurrent cryptococcosis. Treatment with fluconazole resulted in complete resolution of symptoms. Details of the case are presented and clinical implications are discussed.

Lung injury after experimental smoke inhalation: particle-associated changes in alveolar macrophages

The role of smoke particles in the pathogenesis of smoke inhalation lung injury is enigmatic. We report an experimental model that facilitates study of this issue. Mice were exposed over a 30-min period to smoke released from a flexible polyurethane foam, heated at 400 degrees C. The smoke was initially rich in spherical, isocyanate-containing particles of respirable sizes. Respirations were labored at the end of the exposure and worsened with time and were accompanied by increases in lung water. Bronchoalveolar lavage revealed a significant reduction in the total number of alveolar macrophages in the fluid recovered from the lungs as early as 2 hr after exposure. Macrophage cytoplasm contained numerous smoke particles and decreased numbers of lysosomal-like granules, and the nuclei were often pyknotic. The same recovered lavage fluid contained numerous smoke particles, free lysosomal-like granules, cytoplasmic and nuclear debris, and significant increases in the soluble activity of both the lysosomal marker enzyme and total protein. These findings indicate that there was cell breakdown, including macrophages. Free-radical isocyanates are toxic compounds, and we suggest that after being phagocytized these compounds contribute to the breakdown of macrophages. A pathogenic relationship between these macrophage changes and the acute lung injury can next be explored in this model.

[Detection of the IgE receptor CD23 in sarcoidosis]

In 30 sarcoidosis patients the soluble IgE receptor sCD23 was determined. Compared to healthy controls a marked increase of this molecule could be detected in serum (4.9 versus 0.9 ng/ml). In 19 patients who underwent bronchoscopy a strong expression of CD23 on alveolar macrophages could be demonstrated in immunochemistry compared to healthy controls (40.8 versus 12.6%). Determination of total IgE and anti-IgE antibodies did not allow discrimination between healthy controls and sarcoidosis patients. Our data suggest that alveolar macrophages are an important source for soluble CD23 in serum. CD23 expression might reflect functional activation of macrophages since our results do not appreciate a role for IgE-related reactions in sarcoidosis.

[A case of exogenous lipoid pneumonia probably due to domestic insecticide]

A 61-year-old female was admitted to our hospital because of cough, hemosputum and right chest pain. The P-A and L-R chest films revealed focal consolidation in the right upper filed and mass-like shadow in the right S3. Transbronchial lung biopsy specimens showed collections of lipid-laden macrophages. The lipid material of macrophages in broncholaveolar lavage fluid was stained yellow-orange with Sudan IV. The patient had no difficulty in swallowing and had no history of regular use of oily drugs. Fiberoptic bronchoscopy and chest CT showed no obstruction of bronchi. She had used much domestic insecticide with the doors closed before going to bed every summer and autumn for 10 years. We concluded that the domestic insecticide containing mineral oil had resulted in exogenous lipoid pneumonia. Her symptoms and abnormal shadows in chest X-ray film disappeared soon after antimicrobial chemotherapy was started. She is now healthy without recurrence.

Goodpasture's syndrome in aging. An experimental study on the rat. II

The following hypothesis is suggested: if a lung disease is induced in an adult rat, then its lung, in the senile age, will be different from what is considered to be a normal senile lung. In order to demonstrate this, the pulmonary state of two groups of old rats, one of which had suffered from Goodpasture's syndrome in the adult age has been assessed morphometrically. Fifty-three Wistar rats were used. They were divided into two groups: 1) healthy old rats; and 2) diseased old rats. Antipulmonary serum was administered to the latter and they were sacrificed a year later. Making use of a computing system, we calculated the following data for each group: the alveolar chord length, the alveolar wall thickness and the surface of the bronchial-associated lymphoid tissue (BALT). The alveolar macrophages (AM) with haemosiderin which were found in the lung tissue were also counted and the percentage of goblet bronchial cells and that of bronchoalveolar lavage (BAL) cells was also assessed. From the results, the following points should be emphasized: in diseased old rats, an increase in the alveolar chord, a decrease in lymphocytes with an increase in the AM of the BAL, and a decrease in goblet cells and AM with haemosiderin occur, all of which are significant when these rats are compared to healthy old rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Protein profile in bronchoalveolar lavage fluid from patients with sarcoidosis and idiopathic pulmonary fibrosis as revealed by SDS-PAGE electrophoresis and western blot analysis

So far bronchoalveolar lavage (BAL)-protein in interstitial lung disease (ILD) is evaluated by measuring concentrations of single proteins. Due to the high dilution of most proteins in BAL, analysis of protein profile has been disappointing. This study describes a new method to overcome this problem and to reveal a highly differentiated picture of BAL proteins. Eighteen patients with pulmonary sarcoidosis, 18 patients with idiopathic pulmonary fibrosis (IPF) and 22 patients with no clinical, roentgenologic or functional evidence of ILD underwent BAL. Total and differential cell count was performed. Normal values for the control group, a lymphocytic alveolitis in sarcoidosis and a granulocytic alveolitis in IPF-patients were found. Median total protein concentration in sarcoidosis showed an increase five times higher than that of the controls (150 mg 1(-1) and 27 mg 1(-1), respectively) with p < 0.001, IPF protein concentration (58 mg 1(-1)) exceeded twice the control values (0.01 > p > 0.001). Analysis of electrophoretic protein profile in controls with Western blot analysis and the biotin/streptavidin staining system revealed a highly differentiated range of bands. Staining with immunoglobulin antibody identified six bands. Four proteins with molecular weight < 21.000 dalton were present only in sarcoidosis patients. These proteins may be identical with fragmented serum proteins or different cell mediators detected in alveolar cell supernatants. Furthermore, in sarcoidosis the intensity and number of bands with molecular weight more than 67.000 dalton was increased. This gives strong evidence for an injury of the alveolar membrane integrity in the alveolitis during the course of sarcoidosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Goodpasture's syndrome in aging. An experimental study on the rat. I

The following hypothesis is proposed: Experimental lung disease in old rats is different from this disease in adult rats. In order to demonstrate this, we performed a morphometrical evaluation of the pulmonary state of two groups of rats at different ages and to which Goodpasture's syndrome had been induced. 115 Wistar rats were used. They were divided into four different groups as follows: 1) Healthy adult rats which had not been subjected to treatment; 2) diseased adult rats to which antipulmonary serum had been administered; 3) healthy old rats; and 4) diseased old rats. With the help of a computerized system, the length of the alveolar chord, the thickness of the alveolar wall and the surface of the bronchial-associated lymphoid tissue in each group was calculated. We also counted the number of alveolar macrophages (AM) with haemosiderin, the percentage of goblet bronchial cells and that of AM, lymphocytes and polymorphonuclear leukocytes of the broncho-alveolar lavage (BAL). The following results were obtained. When related to the diseased adult rats, the diseased old rats showed an increase in the alveolar chord and a decrease in the thickness of the alveolar wall, as well as in the number of AM with haemosiderin, goblet cells and BAL lymphocytes. These results support the proposed hypotheses, since the diseased adult animals showed signs of alveolar inflammation with interstitial edema, while in the diseased old animals these results are compatible with emphysema.

Increased expression of human leukocyte antigen-DR on pulmonary macrophages in bronchopulmonary dysplasia

We used an immunoperoxidase method to examine the expression of the immune activation marker HLA-DR on pulmonary tissue obtained at autopsy from 14 patients dying of bronchopulmonary dysplasia. Controls consisted of 16 age-matched, sex-matched children dying of noncardiac, nonrespiratory, noninfectious illnesses or as a result of motor vehicle accidents. We did not observe aberrant expression of HLA-DR on pulmonary endothelial cells. Positive staining appeared exclusively on macrophages. We quantitated the expression of antigen by counting the number of positive macrophages and total macrophages/monocytes per high power field. Bronchopulmonary dysplasia patients displayed significantly greater numbers of both positive and total macrophages compared with the control group (p < 0.05). The percent positive macrophages also was significantly higher in the bronchopulmonary dysplasia patients (p < 0.005). We also examined a group of patients dying with infant respiratory distress syndrome. There was no significant difference in number of total macrophages in this group compared with age-matched controls.

Coclastogenicity of ethanol with cigarette smoke in rat erythroblasts and anticlastogenicity in alveolar macrophages

A series of experiments was carried out to assess cytotoxic and cytogenetic effects in bone marrow polychromatic erythrocytes (PCE) and pulmonary alveolar macrophages (PAM) resulting from individual or combined exposure of male BD6 rats to ethanol, cigarette smoke and Aroclor 1254. Addition of 5% ethanol to drinking water did not affect the micronucleus frequency but consistently enhanced the proportion of polynucleated PAM. Moreover, the higher concentration used (10%) was cytotoxic in the bone marrow. Whole-body exposure to cigarette smoke elevated the micronucleus frequency in both PCE (4.0-4.4-fold) and PAM (2.0-3.6-fold) and enhanced the frequency of polynucleated PAM. After 3 weeks of combined exposure, ethanol produced contrasting effects in smoke-exposed rats, i.e. an increase of micronuclei in PCE and a decrease in PAM. An i.p. injection of Aroclor 1254 was per se devoid of any influence on the monitored parameters but tended to attenuate the cytotoxic and cytogenetic changes produced by cigarette smoke or ethanol in both types of cell.

Dual infection with canine distemper virus and infectious canine hepatitis virus (canine adenovirus type 1) in a dog

A 72-day-old, female, Golden Retriever dog showed anorexia, coughing, nasal discharge, diarrhea and hematochezia, and died on the 15th clinical day. Pathological examination revealed dual infection with canine distemper virus (CDV) and canine adenovirus (CAV). CAV inclusion bodies occurred only in the liver, and biliary and respiratory system, whereas CDV inclusions were demonstrated in the visceral organs systematically. The CAV inclusions were associated with multifocal hepatocellular necrosis and edematous swelling of the wall of the gall bladder, suggesting infectious canine hepatitis virus (canine adenovirus type 1) infection.

[Pulmonary macrophages in rats after hemithoracic irradiation: analysis of morphology and expression of surface antigen]

The pathogenesis of radiation pneumonitis is not completely understood. The long latent period and involvement of unirradiated lung tissue may indicate an immune reaction in the injurious process of irradiated lung. To investigate the role of pulmonary macrophages in radiation pneumonitis, morphology and membrane antigen expression of pulmonary macrophages were studied in irradiated rat lung tissue following 4000 R hemithoracic irradiation. Lungs were explanted at 2, 4, 6, 8, 16, and 28 weeks after irradiation. Cryosections of irradiated lung tissue were immunohistochemically studied, and alveolar macrophages in bronchoalveolar lavage fluid were also analyzed using monoclonal antibodies to rat major histocompatibility complex (MHC) antigens and macrophages with flow cytometry. Macrophage subpopulations were analyzed using a panel of monoclonal antibodies to MHC class I (HAM2), MHC class II (OX6) and macrophage differentiation antigens (ED1, ED2, ED3). Alveolar macrophages in bronchoalveolar lavage were morphologically studied by smear and flow cytometry of forward light scatter and 90 degrees light scatter. At 2 weeks after irradiation, when histological changes did not appear, small lymphocyte-like macrophages and large foamy macrophages were observed in both the smear and histograms by flow cytometry. At 4, 6, and 8 weeks after irradiation, these new populations had markedly increased. However, at 16 and 28 weeks after irradiation, the size and shape of alveolar macrophages had returned to normal. In the expression of macrophage membrane antigens, an increase in the frequency of MHC class II+ cells in lavaged cells appeared at 2 weeks after irradiation, and became significant at 4 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

Pulmonary sarcoidosis in children: serial evaluation of bronchoalveolar lavage cells during corticosteroid treatment

The clinical course of sarcoidosis in children has not been well defined. Eight children with symptomatic sarcoidosis included in this study underwent pulmonary function tests and bronchoscopy with bronchoalveolar lavage (BAL) before treatment and during steroid therapy. At the start of therapy, functional parameters, mostly dynamic lung compliance and lung transfer factor for CO, were impaired. This was associated with abnormalities of BAL cell populations: increased total cell number with a high proportion of lymphocytes, modifications of lymphocyte subpopulation with an elevated CD4+/CD8+ ratio, and enhanced ability of alveolar macrophages to release hydrogen peroxide. Although respiratory abnormalities seemed to be similar at the initial stage of sarcoidosis in children and adults, the course of the disease appeared to be different. Despite the absence of respiratory symptoms and disappearance of chest radiographic abnormalities on prolonged steroid treatment, we found slow improvement of pulmonary functions associated with persistence of BAL lymphocytosis and elevated CD4+/CD8+ ratios. However, the ability of alveolar macrophages to release hydrogen peroxide was significantly reduced after 6 months of steroid treatment, and it remained identical to the control group. Therefore, the evaluation of disease activity appears to be critical for therapy in pediatrics, and for this purpose studies of alveolar macrophage activation may be of particular interest.

Amount of Pneumocystis carinii and degree of acute lung inflammation in HIV-associated P carinii pneumonia

Correlations between semiquantitative amounts of Pneumocystis carinii (PC), the degree of inflammation, and the severity of pneumonia were analyzed in 58 patients with PC pneumonia (PCP). Material from both transbronchial biopsies (TBBs; n = 39) and bronchoalveolar lavage fluid (BALF; n = 57) was examined. In the TBB the amount of PC correlated strongly with overall inflammation in the interstitium (Kendall correlation coefficient [Kcc] = 0.59; p < 0.0001), type 2 pneumocyte proliferation, and edema formation. The amount of PC in the TBB also correlated with interstitial accumulation of neutrophils (Kcc = 0.54; p = 0.0001), lymphocytes, and macrophages. In BALF the amount of PC correlated with edema formation and type 2 pneumocyte proliferation in the TBB but not with the percentage of neutrophils, lymphocytes, or macrophages in BALF. The amount of PC in the BALF and the percentage of neutrophils in the BALF correlated significantly with Po2 and the serum lactate dehydrogenase (LDH) level. Neither short-term nor long-term survival was affected by the amount of PC, inflammatory markers in the TBB, inflammatory cells in BALF, Po2, or the serum LDH levels. In conclusion, the amount of PC is associated with the extent of the acute inflammatory reaction in the lung in PCP associated with human immunodeficiency virus (HIV).

Intravenous zymosan-A challenge induces an alveolar inflammatory response

The purpose of this study was to evaluate the ability of intravenous zymosan-A (ZyA) challenge to induce an alveolar inflammatory response as indicated by inflammatory changes among lung lavage cells. The organ distribution of 1 mg of [51Cr]ZyA revealed that immediately following intravenous challenge of female ICR mice approximately 81% of the total cpm injected was associated with pulmonary tissue. Approximately 15% of the injected cpm was associated with the peripheral blood, liver, and spleen. ZyA translocated from the vascular compartment into pulmonary alveoli and was detected within polymorphonuclear neutrophils (PMN) and alveolar macrophages (AM) 18 h after intravenous challenge. PMN numbers among lung lavage cells increased beginning one day after challenge to a peak of approximately 5 x 10(5) PMNs by day 3 after challenge. The PMN response subsided by day 5 after challenge. There was no significant increase in the numbers of AM during the first week after intravenous ZyA; however, the number of AM increased from approximately 5 x 10(5) AM on day 1 after challenge to approximately 1.1 x 10(6) AM by day 5 after challenge. Within 24 h of intravenous ZyA, the number of AM in S phase of the cell cycle increased from approximately 2.5 x 10(4) AM one day after challenge to 1.1 x 10(5) AM in S phase five days after challenge. The data suggest that intravenous ZyA localized within pulmonary tissue immediately following intravenous challenge and translocated into the alveolar compartment where ZyA particles were found within phagocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Patterns of secretion of transforming growth factor-alpha (TGF-alpha) in experimental silicosis. Acute and subacute effects of cristobalite exposure in the rat

Transforming growth factor-alpha (TGF-alpha) a cytokine having potent mitogenic activity for epithelial and mesenchymal cells, may play a role in the lung remodeling of silicosis. Lung macrophages are among the major cells producing TGF-alpha in a lung tissue. A pivotal event in the cascade of pathologic events leading to pulmonary silicosis is the interaction between inhaled silica and macrophages. TGF-alpha may be critical in directing the proliferation of type II pneumocytes that characterize silicosis. An inhalation model of brief exposure of pathogen-restricted male rats to 25 mg/M3 cristobalite, a highly reactive form of silicon dioxide was used to study experimental silicosis. This model is characterized by a rapid, intense, and sustained increase in macrophages, neutrophils, and lymphocytes in both alveolar and interstitial compartments of the lung. TGF-alpha was measured in an A431 cell proliferation assay made specific with the use of anti-TGF-alpha neutralizing antiserum in epithelial lining fluid (ELF) and conditioned media harvested from cultured alveolar and interstitial macrophages. Soluble TGF-alpha levels found in ELF were slightly elevated above control values during the exposure period, then increased 5-fold during the 20 weeks after the 8-day exposure period. Secretion of TGF-alpha by macrophages was elevated during exposure to cristobalite but then fell during the early post exposure period. Marked elevations in TGF-alpha secretion from both interstitial and alveolar macrophages (10- and 12-fold, respectively) occurred 8-16 weeks after cessation of exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Pulmonary giant cells and their significance for the diagnosis of asphyxiation

This study was performed to prove whether the detection of polynuclear giant cells in lungs is useful for the diagnosis of asphyxiation due to throttling or strangulation. Therefore, lung specimens of 54 individuals with different natural and unnatural causes of death were investigated. In most lungs examined numerous alveolar macrophages with 1-2 nuclei were found. Polynuclear giant cells, which were arbitrarily defined as alveolar macrophages containing 3 or more nuclei, were observed in all groups investigated except in the cases of hypoxia due to covering the head with plastic bags. Apparent differences between the other groups in particular an increased number in cases of throttling or strangulation, could not be observed. Immunohistochemical investigations confirmed the hypothesis that the observed polynuclear giant cells were derived from alveolar macrophages. The immunohistochemical analysis of the proliferation marker antigen Ki 67 revealed no positive reaction in the nuclei of polynuclear giant cells indicating that these cells had not developed shortly before death by endomitosis as an adaptative change following reduction in oxygen supply. The results provide evidence that the detection of pulmonary polynuclear giant cells cannot be used as a practical indicator for death by asphyxiation due to throttling or strangulation.

Peripolesis in alveolar sarcoidosis

We observed that in bronchoalveolar lavages (BAL) of patients with active sarcoidosis (SARC) a mononuclear cell infiltrate is present that often contains clusters consisting of lymphocytes adhering to a macrophage. In order to investigate what kind of cellular interactions are involved in such a process, cell suspensions obtained from BAL of patients with SARC or extrinsic allergic alveolitis (EAA) were cultured for 1 to 2 days, during which time lapse cinematography was applied. We were able to show that such clusters consist of lymphocytes gathered around a macrophage. This is known as peripolesis. Peripolesis, as observed in our BAL, could last for some minutes or for some hours during which time a number of lymphocytes were moving around a single alveolar macrophage, without losing contact with the macrophage. Short interactions were mostly observed in EAA, whereas SARC was characterized by long periods of lymphocyte-macrophage cooperation. We also found a correlation between the time-dependent peripolesis t > 30 min/t < 30 min and the CD4/CD8 ratio. Although the precise mechanisms of peripolesis are not well understood, some interactions between lymphocytes and macrophages have now become more comprehensive.

Siderophages in the lung of drug addicts

According to literature, siderophages are a characteristic histological finding in the lung of deceased drug addicts (IVDA). It was the aim of our study to evaluate their pathognomonic significance. The lungs of 591 drug deaths in Hamburg were examined histologically for siderophages in two series, with different 'Berlinerblau' (Prussian blue) staining methods. The first series (investigation period 1980-1990) showed iron-containing macrophages in 36 of 420 drug deaths (8.6%) compared with a control-group (healthy young persons dying from unnatural causes of death) in which only one was positive (2%). In a second series, using a more sensitive staining method, 80 of 171 drug deaths (47%) in the year 1991 showed siderophages, whilst in a control-group, 17 of 35 cases (49%) were positive. According to our findings the pathognomonic value of siderophages in the lung of IVDA is doubtful. There is a need for further histochemical and ultrastructural investigations concerning the morphology and etiology of pulmonary macrophages in IVDA.

X-ray microanalysis of cultured alveolar macrophages with phospholipidosis

When administered to humans and animals, the iodine-containing drug amiodarone can cause pulmonary toxicity. As part of the pulmonary response to amiodarone, the drug and its principal metabolite, desethylamiodarone, accumulate in alveolar macrophages. Little is known about the susceptibility of lungs with preexisting damage to amiodarone administration. A number of chemicals can cause pulmonary phospholipidosis in humans and animals. To study the effect of a preexisting phospholipidosis on the intracellular accumulation of amiodarone and desethylamiodarone, rats were treated with chlorphentermine to induce a phospholipidosis in alveolar macrophages. The cells were recovered from the lungs by pulmonary lavage and placed in cell culture. They were then exposed to the same concentration of either amiodarone or desethylamiodarone. The intracellular distribution of each drug was quantified by measuring the associated iodine signal using X-ray microanalysis of freeze-dried cryosections of cells. Both drugs accumulated in lipid-rich amorphous bodies which correspond to lysosomally derived lamellar structures observed in conventional plastic sections. The level of desethylamiodarone exceeded that of amiodarone in the amorphous bodies. With both drugs, a higher concentration of iodine was present at the outer edges of the amorphous bodies compared to that in the center core. This suggests that the drugs are unable to freely penetrate the performed structures. By monitoring the concentrations of sodium and potassium ions within the nucleus, it was determined that chlorphentermine treatment disrupted the ionic distribution in the cells. Exposure to amiodarone, but not desethylamiodarone, resulted in further changes in sodium and potassium levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Expression of tumour necrosis factor-alpha in cryptogenic fibrosing alveolitis

We have studied 15 cases of cryptogenic fibrosing alveolitis stained with a monoclonal antibody reactive with human tumour necrosis factor-alpha (TNF alpha), a cytokine that has been implicated in inflammation and fibrosis. Seven were examples of lone cryptogenic fibrosing alveolitis and eight were examples of cryptogenic fibrosing alveolitis in patients with systemic sclerosis. There was widespread staining of epithelial cells, particularly hyperplastic type II pneumocytes. Macrophages stained only weakly. In a control group of 10 patients dying of unrelated conditions, staining for TNF alpha was weak and, in the alveolar epithelium, was confined to a very occasional type II pneumocyte. The strong expression of TNF alpha in hyperplastic type II pneumocytes suggests that TNF alpha produced during alveolar epithelial regeneration may play a part in the fibrosis seen in this disease.

Mechanisms of hydroxyl free radical-induced cellular injury and calcium overloading in alveolar macrophages

Excessive production of reactive oxygen radicals by alveolar macrophages is proposed to play an important role in oxidative lung injury. A major product oxygen radical formation is the highly reactive hydroxyl radical (.OH) generated via a biologic Fenton reaction. In addition to its known ability to induce lipid peroxidation, recent studies have suggested that the .OH may exert its cytotoxic effect through the alteration of [Ca2+]i homeostasis. To test this potential mechanism as well as to investigate the relationship between .OH and Ca2+ overloading in cytotoxic injury, isolated rat alveolar macrophages were exposed to externally generated radical system, H2O2 (0.01 to 1 mM) and Fe2+ (1 mM) and their [Ca2+]i levels and cell injury were monitored using quantitative fluorescence microscopy with the aid of the specific Ca2+ indicator, Fura-2, and membrane integrity indicator, propidium iodide. Electron spin resonance measurements using the spin trap 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) confirmed the production of the .OH radical by this system. Upon the addition of the radicals, the macrophages displayed a rapid initial rise in [Ca2+]i which was followed by a slower but more pronounced [Ca2+]i elevation that reached a level 3 to 5 times higher than the basal level. This process preceded cell death as evident by nuclear propidium iodide fluorescence. Depletion of extracellular Ca2+ inhibited both the [Ca2+]i response and cell injury. Preincubation of the cells with the Ca2+ channel blocker verapamil or .OH radical scavenger mannitol similarly inhibited the [Ca2+]i rise and loss of viability. Firefly luciferase assay of cellular ATP content demonstrated that the alterations in [Ca2+]i following .OH treatment preceded the depletion of ATP.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in bronchoalveolar lavage inflammatory cells in asthmatic patients treated with high dose inhaled beclomethasone dipropionate

Using serial bronchoalveolar lavage (BAL), we have studied changes in the airway inflammatory cell populations in 20 asthmatic patients, before and after treatment with inhaled beclomethasone dipropionate (BDP), 2,000 micrograms daily in an uncontrolled study. There was a significant improvement in asthma severity, as measured by symptom score and airways responsiveness, and there were significant reductions in the total BAL eosinophil, epithelial cell and mast cell counts, with a significant increase in the percentage BAL lymphocyte count. No significant correlations were found between the changes in airway inflammatory cell numbers and the reduction in asthma severity. In contrast, the fall in ROS generation by the pulmonary macrophage and granulocyte populations was nonsignificant, but the improvement in airways responsiveness was positively correlated to the reduction in the unstimulated pulmonary macrophage activity. Although these data are uncontrolled, the results are compatible with previous studies in suggesting an effect of steroids on the eosinophil, mast cell and epithelial cell in asthmatic airways. They also highlight the probable importance of the luminal lymphocyte population and pulmonary macrophage activation within the asthmatic airway, the beneficial modulatory effect of inhaled BDP treatment upon them, and the relative steroid-resistance of pulmonary inflammatory cell activity.

Lung parenchymal changes secondary to cigarette smoking: pathologic-CT correlations

To determine the histopathologic basis for computed tomographic (CT) interpretation of smokers' lung and the accuracy of CT in the detection of alterations related to cigarette smoking, parenchymal lung lesions were studied from 41 heavy smokers who underwent thoracotomy for removal of a solitary pulmonary nodule. CT scanning of the resected lungs, corresponding exactly to the sections seen on preoperative CT scans, resulted in the following pathologic-CT correlations. Areas of ground-glass attenuation seen on preoperative CT scans (n = 11 [27%]) were related to three main histologic features: (a) accumulation of pigmented macrophages and mucus in the alveolar spaces, associated with mild interstitial inflammation and/or fibrosis (n = 7); (b) thickening of the alveolar walls with inflammatory cells with normal alveolar spaces (n = 3); and (c) presence of organizing alveolitis (n = 1). Parenchymal micronodules depicted presurgically (n = 4 [10%]) corresponded to bronchiolectases with peribronchiolar fibrosis (n = 4) associated with obliterative bronchiolitis in one patient. When emphysema was detected presurgically (n = 21 [51%]), it was always present at pathologic study to a higher extent than initially suspected.

Macrophage inflammatory proteins 1 and 2: expression by rat alveolar macrophages, fibroblasts, and epithelial cells and in rat lung after mineral dust exposure

Macrophage inflammatory proteins 1 alpha and 2 (MIP-1 alpha, MIP-2) are members of a growing family of cytokines thought to play a role in host defense. MIP-1 alpha and MIP-2 were previously identified in the mouse and shown to stimulate inflammatory cell recruitment. To better understand the potential role of MIP-1 alpha and MIP-2 in lung defense, we investigated the ability of rat lung cells to express mRNA for and/or secrete MIP-1 alpha and MIP-2 proteins in vitro and characterized expression of these cytokines in rat lung after in vivo exposure to silica (SiO2) or titanium dioxide (TiO2). In response to lipopolysaccharide, rat alveolar macrophages expressed increased levels of MIP-1 alpha and MIP-2 mRNA and secreted proteins (identified by N-terminal sequencing) homologous to mouse MIP-1 alpha and MIP-2. Rat alveolar macrophage MIP-1 alpha and MIP-2 mRNA expression was also increased by tumor necrosis factor-alpha (TNF) and adherence to plastic. Studies with a rat fibroblast and epithelial cell line demonstrated that MIP-2, but not MIP-1 alpha, expression can be detected in these cells after stimulation with TNF. Intratracheal instillation studies with SiO2 and TiO2 showed that inflammatory doses of these dusts increase MIP-1 alpha and MIP-2 mRNA expression in whole lung and that increased gene expression preceded the accumulation of inflammatory cells.(ABSTRACT TRUNCATED AT 250 WORDS)

An immunohistochemical study on the cytogenetic origin of pulmonary multinucleate giant cells in porcine dermatosis vegetans

The origin of pulmonary multinucleate giant cells (MGC) in porcine dermatosis vegetans was studied in six Norwegian Landrace pigs ages 4 (male), 5 (female), 6 (female), 10 (female), and 12 (one male, one female) weeks, using an avidin biotin peroxidase and alkaline phosphatase complex immunohistochemical method on sections of formalin- and ethanol-fixed and frozen tissue specimens. Well-characterized, commercially available antisera/monoclonal antibodies to keratin, vimentin, lysozyme, a monocytic antigen, and a myelomonocytic antigen were used. The immunoreactivity to intermediate-sized filaments in MGC was negative for keratins and positive for vimentin. In addition, a positive reaction was found in alveolar macrophages, chondrocytes, fibrocytes, alveolar lymphocytes, and granulocytes in ethanol-fixed tissue. Marked masking was observed in formalin-fixed tissue. Antilysozyme antiserum gave a positive cytoplasmic reaction in alveolar macrophages and MGC, although the reaction was variable in ethanol-fixed tissue. In trypsinized formalin-fixed tissue, a moderate and more consistent cytoplasmic reaction was observed in alveolar macrophages and MGC. Two monoclonal antibodies that identify human cells of the MMS, EMB 11 and Mac 387, were negative for EMB 11 in ethanol-fixed and frozen sections, whereas Mac 387 showed a positive and specific cytoplasmic immunoreaction in alveolar macrophages and small MGC in ethanol- and formalin-fixed tissue. Pulmonary MGC in dermatosis vegetans are derived from mesenchymal cells, and substantial evidence is provided in support of a monocyte/macrophage origin based on a positive reaction for lysozyme and a myelomonocytic antigen. The importance of adequate fixatives for immunohistochemical demonstration of cell-specific markers is clearly shown.

[Significance of short-term cytotoxicity tests for hygienic assessment of industrial aerosols]

The evaluation of low-soluble particles toxicity for human phagocytes (primarily, for macrophages) was proved to have advantages in predicting their effects on the human body and in rapid toxico-hygienic regulation. The preference is given to tests "in vitro". If comparative toxicities of substances in group are discordant according to different "in vitro" tests the decision must be made after the "in vivo" evaluation of cytotoxicity: in 24 hours after the intratracheal administration of small doses of these low-soluble particles the bronchoalveolar lavage is examined cytologically. Reliable neutrophilia in lavage is of great value.

How silicosis and coal workers' pneumoconiosis develop--a cellular assessment

In vitro and in vivo animal studies, as well as human investigations, strongly support the role of macrophage products in the development and progression of silicosis and coal workers' pneumoconiosis. Such products include enzymes and reactive oxygen species which may cause lung damage; cytokines which recruit and/or activate polymorphonuclear leukocytes and thus result in further oxidant damage to the lung; and fibrogenic factors which induce fibroblast proliferation and collagen synthesis. This mechanistic understanding of pulmonary disease should assist in developing strategies for prevention and treatment.