Variable extrathoracic airflow obstruction and chronic laryngotracheitis in Gulf War veterans

STUDY OBJECTIVES

To study the flow-volume loop for evidence of variable extrathoracic airflow obstruction in Persian Gulf War veterans.

DESIGN

Retrospective case-control, single-center study.

SETTING

The pulmonary division of an academic health-care center.

SUBJECTS

A convenience sample of the Persian Gulf Registry.

MEASUREMENTS AND INTERVENTIONS

(1) Midvital capacity ratio (ratio of maximum forced midexpiratory to maximum forced midinspiratory flow). This ratio is the criterion standard for the diagnosis of variable extrathoracic airflow obstruction. (2) Evaluation of the anatomy and function of the extrathoracic airway by fiberoptic bronchoscopy. (3) Further investigation into the airway abnormality by histologic evaluation of tracheal biopsy samples in Gulf War veterans only.

RESULTS

Midvital capacity was > 1.0 in 32 of 37 Gulf War veterans compared with only 11 of 38 control subjects. The mean (+/-SD) value was 1.37+/-0.4 among Gulf War veterans and 0.88+/-0.3 among control subjects (p=0.0000005). FVC and its ratio to FEV1 were normal in all these subjects. Bronchoscopy showed inflamed larynx and trachea in all (n=17) Gulf War veterans. Histologic study showed chronic inflammation of the trachea in everyone (n=12) who had an adequate biopsy sample.

CONCLUSION

Physicians should be made aware of the presence of chronic inflammation of the upper airways and inspiratory airflow limitation in a number of Gulf War veterans.

Requirements for allergen-induced airway hyperreactivity in T and B cell-deficient mice

BACKGROUND

The pathogenesis of asthma is believed to reflect antigen-induced airway inflammation leading to the recruitment of eosinophils and activation of mast cells through cell-associated IgE. Controversies persist however, regarding the relative importance of different pathogenic cells and effector molecules.

MATERIALS AND METHODS

A variety of gene-targeted mice were examined for the induction of cholinergic airway hyperresponsiveness (AH), allergic airway inflammation, mucus production, and serum IgE reactivity following intratracheal challenge with a potent allergen. AH was determined using whole-body plethysmography following acetylcholine challenge. Where possible, results were confirmed using neutralizing antibodies and cell-specific reconstitution of immune deficient mice.

RESULTS

T and B cell-deficient, recombinase-activating-gene-deficient mice (RAG -/-) failed to develop significant allergic inflammation and AH following allergen challenge. Reconstitution of RAG -/- mice with CD4+ T cells alone was sufficient to restore allergen-induced AH, allergic inflammation, and goblet cell hyperplasia, but not IgE reactivity. Sensitized B cell-deficient mice also developed airway hyperreactivity and lung inflammation comparable to that of wild-type animals, confirming that antibodies were dispensable. Treatment with neutralizing anti-IL-4 antibody or sensitization of IL-4-deficient mice resulted in loss of airway hyperreactivity, whereas treatment with anti-IL-5 antibody or sensitization of IL-5-deficient mice had no effect.

CONCLUSIONS

In mice, CD4+ T cells are alone sufficient to mediate many of the pathognomonic changes that occur in human asthma by a mechanism dependent upon IL-4, but independent of IL-5, IgE, or both. Clarification of the role played by CD4+ T cells is likely to stimulate important therapeutic advances in treatment of asthma.

Upregulation of neuropeptides and neuropeptide receptors in a murine model of immune inflammation in lung parenchyma

The lung is richly supplied with peptidergic nerves that store and secrete substance P (SP), vasoactive intestinal peptide (VIP), and other neuropeptides known to potently modulate leukocyte function in vitro and airway inflammation in vivo. To investigate and characterize neuromodulation of immune responses compartmentalized in lung parenchyma, neuropeptide release and expression of neuropeptide receptors were studied in lungs of antigen-primed C57BL/6 mice after intratracheal challenge with sheep erythrocytes. The concentrations of cytokines in bronchoalveolar lavage (BAL) fluid rose early and peaked on day 1 for interleukin (IL)-2, interferon gamma, and IL-10; days 1 to 2 for IL-6; and day 3 for IL-4, whereas the total number and different types of leukocytes in BAL fluid peaked subsequently on days 4 to 6 after i.t. antigen challenge. Immunoreactive SP and VIP in BAL fluid increased maximally to nanomolar concentrations on days 1 to 3 and 2 to 7, respectively in lungs undergoing immune responses. The high-affinity SP receptor (NK-1 R), and VIP types I (VIPR1) and II (VIPR2) receptors were localized by immunohistochemistry to surface membranes of mononuclear leukocytes and granulocytes in perivascular, peribronchiolar, and alveolar inflammatory infiltrates during immune responses. As quantified by reverse transcription-polymerase chain reaction, significant increases were observed in levels of BAL lymphocyte mRNA encoding NK-1 R (days 2 to 4), VIPR1 (days 2 to 4), and VIPR2 (days 4 to 6), and in alveolar macrophage mRNA encoding NK-1 R (days 2 to 6) and VIPR1 (days 2 to 4), but not VIPR2. Systemic treatment of mice with a selective, nonpeptide NK-1 R antagonist reduced significantly the total numbers of leukocytes, lymphocytes, and granulocytes retrieved by BAL on day 5 of the pulmonary immune response. The results indicate that SP and VIP are secreted locally during pulmonary immune responses, and are recognized by leukocytes infiltrating lung tissue, and thus their interaction may regulate the recruitment and functions of immune cells in lung parenchyma.

Role of CD8+ lymphocytes in host defense against Pneumocystis carinii in mice

An improved understanding of host defense against Pneumocystis carinii could provide novel therapeutic modalities directed against this opportunistic pathogen. Immunodeficient mouse models confirm the role of CD4+ lymphocytes in defense against P. carinii, but the role of CD8+ lymphocytes is controversial. BALB/c mice specifically depleted of CD4+ lymphocytes are susceptible to P. carinii, recruiting large numbers of CD8+ lymphocytes to their lungs during infection. Because of this recruitment, we hypothesized that CD8+ lymphocytes could participate in host defense against P. carinii. BALB/c mice were depleted of CD4+ lymphocytes, CD8+ lymphocytes, or both CD4+ and CD8+ lymphocytes. All mice were then inoculated intratracheally with P. carinii. Mice depleted of CD4+ lymphocytes became moderately infected with P. carinii. Mice depleted of CD8+ lymphocytes cleared the inoculum, indicating that CD8+ lymphocytes are unnecessary for defense when CD4+ lymphocytes are available. However, mice depleted of both CD4+ and CD8+ lymphocytes became significantly more intensely infected than mice depleted of CD4+ lymphocytes alone. Therefore, CD8+ lymphocytes participate in defense against P. carinii in vivo during depletion of CD4+ lymphocytes. To determine the mechanisms of this protection, CD8+ lymphocytes were purified from the lungs of CD4-depleted mice during infection. Lung CD8+ lymphocytes proliferated in response to P. carinii antigen and elaborated interferon-gamma in vitro. Thus CD8+ lymphocytes provide defense against P. carinii in vivo, and the elaboration of interferon-gamma likely represents one important mechanism of defense. During states of CD4+ lymphocyte depletion, the modulation of CD8+ lymphocyte function may provide alternative approaches to the host defense against opportunistic pathogens.

Interleukin 4, but not interleukin 5 or eosinophils, is required in a murine model of acute airway hyperreactivity

Reversible airway hyperreactivity underlies the pathophysiology of asthma, yet the precise mediators of the response remain unclear. Human studies have correlated aberrant activation of T helper (Th) 2-like effector systems in the airways with disease. A murine model of airway hyperreactivity in response to acetylcholine was established using mice immunized with ovalbumin and challenged with aerosolized antigen. No airway hyperractivity occurred in severe combined immunodeficient mice. Identically immunized BALB/c mice developed an influx of cells, with a predominance of eosinophils and CD4+ T cells, into the lungs and bronchoalveolar lavage fluid at the time that substantial changes in airway pressure and resistance were quantitated. Challenged animals developed marked increases in Th2 cytokine production, eosinophil influx, and serum immunoglobulin E levels. Neutralization of interleukin (IL) 4 using monoclonal antibodies administered during the period of systemic immunization abrogated airway hyperractivity but had little effect on the influx of eosinophils. Administration of anti-IL-4 only during the period of the aerosol challenge did not affect the subsequent response to acetylcholine. Finally, administration of anti-IL-5 antibodies at levels that suppressed eosinophils to < 1% of recruited cells had no effect on the subsequent airway responses. BALB/c mice had significantly greater airway responses than C57BL/6 mice, consistent with enhanced IL-4 responses to antigen in BALB/c mice. Taken together, these data implicate IL-4 generated during the period of lymphocyte priming with antigen in establishing the cascade of responses required to generate airway hyperractivity to inhaled antigen. No role for IL-5 or eosinophils could be demonstrated.

Identification of novel regions of altered DNA copy number in small cell lung tumors

Identification of the genetic alterations that occur in tumors is an important approach to understanding tumorigenesis. We have used comparative genomic hybridization (CGH), a novel molecular cytogenetic method, to identify the gross DNA copy number changes that commonly occur in small cell lung cancer (SCLC). We analyzed ten SCLC tumors (seven primary tumors and three metastases) from eight patients. We found frequent increases in DNA copy number on chromosome arms 5p, 8q, 3q, and Xq and frequent decreases in copy number on chromosome arms 3p, 17p, 5q, 8p, 13q, and 4p. The increase in copy number at 8q24 (MYC) and decreases at 17p13 (TP53), 13q14 (RB), and 3p have previously been identified in SCLC with other methods. Many of the other regions in which we detected common copy number changes have not been reported to be regions of common alteration in SCLC tumors. Comparison of copy number changes between a primary tumor and a metastasis from the same patient showed that they were more closely related to each other than to any of the other tumors. The results of direct CGH analysis of SCLC tumors reported here confirm the existence of copy number changes that we identified previously by using cell lines.

CT quantification of interstitial fibrosis in patients with asbestosis: a comparison of two methods

OBJECTIVE

The likelihood of interstitial lung disease being detected on high-resolution CT scans and having functional significance is often related to the severity of the disease. The extent and severity of the abnormalities seen on high-resolution CT are usually assessed subjectively. This study was undertaken to investigate whether a subjective semiquantitative scoring method or a method using a cumulation of the different high-resolution CT features of asbestosis were comparable in suggesting asbestosis in a group of patients with histopathologic confirmation of disease. A secondary objective was to compare the results of these two high-resolution CT methods with chest radiographs in the same population.

MATERIALS AND METHODS

This study group consisted of 24 patients and six lungs obtained at autopsy. Histopathologic asbestosis was present in 25 of the 30 patients or lungs. The patients or lungs were imaged using selected high-resolution CT scans. The high-resolution CT scans were assessed in two ways. One used a subjective semiquantitative extent and severity score consisting of four levels of severity, while the other was a cumulative score adding the different types of high-resolution abnormalities in asbestosis. The commonest high-resolution CT abnormalities in the cases with confirmed asbestosis were interstitial lines (84%), parenchymal bands (76%), and architectural distortion of secondary pulmonary lobules (56%). Subpleural lines and honeycombing were less frequent. The histopathologic severity of asbestosis was independently graded on a four-point scale. Chest radiographs, when available, were classified according to the International Labor Organization (ILO) classification of pneumoconioses.

RESULTS

With the subjective semiquantitative high-resolution CT severity score, asbestosis was suggested in 16 (64%) instances, all with disease. With the cumulative method, any one type of abnormality was present in 88% of cases with asbestosis, two types in 78%, and three in 56%. However, to include only cases with asbestosis, three different abnormalities had to be present. The high-resolution CT scans were normal or near normal in five instances of asbestosis. Chest radiographs using the ILO classification predicted asbestosis with a lesser frequency than high-resolution CT in this selected population.

CONCLUSION

We conclude that a subjective semiquantitative grading system of the extent and severity of asbestosis and a method using a cumulative addition of the different findings in asbestosis give similar results in suggesting the presence of disease. Thus, for the high-resolution CT detection of asbestosis, a combination of the cumulative number of different findings and an assessment of the extent and severity of the abnormalities could be complimentary. We also conclude that asbestosis can be present histopathologically with a normal or near normal high-resolution CT scan.

Pulmonary aspergillosis: imaging findings with pathologic correlation

Pulmonary involvement with Aspergillus fumigatus is varied and largely dependent on the patient's underlying pulmonary and immune status. Hypersensitivity reactions from inhalation of spores can cause acute allergic alveolitis, and bronchial colonization can cause allergic bronchopulmonary aspergillosis (ABPA). The latter is found mainly in patients with asthma or cystic fibrosis. Mycetomas develop from secondary colonization of preexisting lung cavities. Invasive and semi-invasive aspergillosis affect mostly patients with altered immune status. This essay illustrates the radiologic findings of pulmonary aspergillosis and shows the correlation between the imaging and pathologic findings.

Experimental murine pulmonary cryptococcosis. Differences in pulmonary inflammation and lymphocyte recruitment induced by two encapsulated strains of Cryptococcus neoformans

BACKGROUND

Cryptococcus neoformans, the most common cause of lethal mycosis in AIDS, usually causes only subclinical pneumonitis in normal hosts. However, cryptococcosis can induce various pulmonary inflammatory reactions, and pulmonary cellular immunity is postulated to prevent dissemination. We hypothesized that cryptococcal strains possess different capacities to induce recruitment to the lungs of inflammatory cells, especially lymphocytes, which are necessary for cryptococcal clearance.

EXPERIMENTAL DESIGN

We examined the pulmonary response of CBA/J mice to intratracheal inoculation with C. neoformans of either of two strains: 52D (ATCC 24067), which rarely kills immunocompetent mice; and 145A (ATCC 62070), which is uniformly fatal. From 2-42 days after inoculation, lungs were either examined grossly and microscopically or were enzymatically digested and inflammatory cells counted and analyzed by flow cytometry. At 42 days, organism burden in lung and brain was quantified by colony-forming unit assay.

RESULTS

Pulmonary inflammation differed greatly between the two strains. Strain 52D induced dense perivascular and alveolar inflammation; infection progressed to day 21 and then waned. In contrast, strain 145A induced delayed, meager lymphocytic infiltration and slight alveolitis; organisms grew progressively. Recovery of inflammatory cells increased by day 13 with strain 52D, but not until day 31 with strain 145A. Although all lymphocyte subsets were greater in 52D infection, the disparity was greatest for CD4+ T cells. Nevertheless, lymphocytes from paratracheal nodes of infected mice proliferated in vitro to heat-killed cryptococci, indicating immune recognition of both strains. At day 42, strain 52D lightly infected lungs but not brain, whereas strain 145A heavily infected lungs and brain. CONCLUSIONS; Cryptococcal strains differ in their capacity to induce pulmonary cellular inflammation, especially CD4+ T cell recruitment. Our results suggest that strain-specific difference in the organism's ability to induce (or evade) pulmonary inflammation contributes to the outcome of infection.

Pulmonary lymphocyte recruitment: depletion of CD8+ T cells does not impair the pulmonary immune response to intratracheal antigen

CD8+ T cells predominate in the lungs in hypersensitivity and human immunodeficiency virus-related lymphocytic pneumonitis, but their role in the immunopathogenesis of lung disease is unknown. We have shown that in immunized mice depleted of CD4+ T cells, CD8+ T cells are recruited into the lungs in response to intratracheal antigen challenge with sheep red blood cells (SRBC) (J. Clin. Invest. 1991; 88:1244-1254) or to pulmonary infection with Pneumocystis carinii (Am. J. Respir. Cell Mol. Biol. 1991; 5:186-197), suggesting that recruitment of CD8+ T cells does not depend on CD4+ T cell-derived signals. Because CD8+ T cells themselves produce a variety of chemotactic and immunoregulatory cytokines, CD8+ T cells may be important participants in, and modulators of, pulmonary immune responses. To test this hypothesis, we examined the effects of CD8+ T cell depletion on the generation of a pulmonary immune response in vivo. We monitored the recruitment of mononuclear cells into lungs in the absence of CD8-dependent signals and measured the duration of pulmonary inflammation in the absence of suppressor CD8+ T cells. Primed mice were treated with anti-CD8 monoclonal antibody to deplete CD8+ T cells and subsequently were challenged intratracheally with 5 x 10(8) SRBC. At various times after challenge, total and differential cell counts and lymphocyte phenotypes were measured in bronchoalveolar lavage fluid by flow cytometry and lungs were scored histologically. We found that depletion of CD8+ T cells neither decreased recruitment of immune and inflammatory cells nor prolonged the pulmonary immune response.(ABSTRACT TRUNCATED AT 250 WORDS)

Plexogenic angiopathy in pulmonary intralobar sequestrations: pathogenetic mechanisms

Vascular remodeling to form plexiform (glomoid) lesions is a little-known manifestation of intralobar pulmonary sequestration. We describe histologic and immunohistochemical features of these lesions in resected specimens from three subjects aged 3, 19, and 28 years. The vascular changes, which included medial and intimal thickening, angioblastic proliferation, plexiform lesions, and dilation lesions, occurred in a setting of hypoxia, chronic inflammation, and high pressure and flow via a systemic arterial supply. We demonstrated strong immunoreactivity of the angioblastic tissue and the plexiform lesions with antibodies to muscle actin, alpha-smooth muscle actin, and vimentin, and weak to absent reactivity with antibody to desmin. We suggest that in these sequestrations plexiform lesions develop via angioblastic proliferation at arterial branch points and that dilation lesions develop from subsequent expansion of distal anastomoses.

Primary pulmonary hypertension and human immunodeficiency virus infection in a non-hemophiliac man

We describe clinical and postmortem findings in a 44-year-old man with pulmonary hypertension and infection with the human immunodeficiency virus (HIV-1). Plexogenic angiopathy and veno-occlusive lesions were present, in addition to a mild, patchy pulmonary interstitial lymphoid infiltrate. The clinical data for 14 previously reported cases of HIV-associated primary pulmonary hypertension are summarized. We speculate that these vascular changes may be due to damage from a specific immune response to HIV.

Requirement of CD4-positive T cells for cellular recruitment to the lungs of mice in response to a particulate intratracheal antigen

To determine whether CD4+ T cells participate in the recruitment of other lymphocyte subsets to the lungs, we examined pulmonary immune responses in C57BL/6 mice treated in vivo with the MAb GK1.5, either intact (which depletes CD4+ cells) or as F(ab')2 fragments (which block CD4 molecules). After intratracheal challenge with sheep erythrocytes, antigen-primed mice treated with intact GK1.5 had marked decreases in lymphocytes and macrophages in bronchoalveolar lavage fluid and minimal parenchymal inflammation, compared to primed mice treated with an isotype-matched irrelevant antibody or with no antibody. At 7 d after challenge, flow cytometric analysis showed that numbers of Thy 1.2+ and B220+ cells, but not of CD8+ cells, were markedly decreased in lavage fluid of CD4-depleted mice. Similar suppression of the pulmonary immune response to intratracheal challenge was found in primed mice injected repeatedly with F(ab')2 fragments of GK1.5, which did not deplete CD4+ T cells, and in athymic mice. These findings indicate that, in response to a single intratracheal antigen challenge, recruitment to the lungs of leukocytes other than CD8+ T cells depends largely on CD4+ T cells, possibly because of signals requiring T cell activation via interactions with antigen-presenting cells.

Inflammatory responses to Pneumocystis carinii in mice selectively depleted of helper T lymphocytes

Pneumocystis carinii is the most important pulmonary pathogen in patients with the acquired immunodeficiency syndrome, but host defenses against P. carinii are not well characterized. We recently reported an experimental model of P. carinii infection, in which mice selectively depleted of CD4+ lymphocytes develop pulmonary infection after inoculation with P. carinii. In the current study, we compared lung inflammatory responses to P. carinii inoculation in CD4-depleted mice and in normal mice in order to further characterize host defenses against P. carinii. We hypothesized that depletion of CD4+ lymphocytes would prevent recruitment and activation of inflammatory cells in the lungs of these mice, allowing progressive infection with P. carinii. We found that CD4-depleted mice were unable to recruit CD4+ lymphocytes into their lungs and developed progressive infection with P. carinii, but mounted exuberant inflammatory responses to the organisms. These inflammatory responses were characterized by perivascular infiltration with mononuclear cells, increases in cell numbers in bronchoalveolar lavage (particularly CD8+ lymphocytes), and activation of alveolar macrophages (enhanced Ia antigen expression). In contrast, normal mice recruited CD4+ lymphocytes into their lungs and eliminated organisms with only minimal inflammatory responses. We conclude that depletion of CD4+ lymphocytes does not prevent the recruitment and activation of inflammatory cells in the lung. These inflammatory responses occur by mechanisms independent of CD4+ lymphocytes and are insufficient to provide effective host defense against P. carinii.

Intravascular (angiotropic) large-cell lymphoma ('malignant angioendotheliomatosis') with small vessel pulmonary vascular obstruction and hypercalcemia

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Histologic analysis of an immune response in the lung parenchyma of mice. Angiopathy accompanies inflammatory cell influx

To determine the histologic changes occurring during a pulmonary immune response, the lungs of antigen-primed C57BL/6 mice were examined on various days after intratracheal challenge with 10(8) sheep erythrocytes. The response was characterized by 1) dense perivascular aggregates composed largely of mononuclear cells; 2) endothelial cell hypertrophy and subendothelial inflammatory cell collections in vessels of a variety of sizes; 3) variable degrees of focal, reversible vascular injury (angiopathy) of both muscular arteries and small veins; and 4) increased cellularity of alveolar walls. Inflammatory cells appeared to emanate from small veins and venules and from minute thin-walled vessels adjacent to large arteries. The reaction peaked at 3 to 4 days and then gradually declined over a period of 6 weeks, never quite reaching baseline. We believe that this experimental model will be an important means of further defining both the mechanisms of lymphocyte entry to the lungs in response to antigen and the factors controlling the pathogenesis of related angiopathies.

Chylothorax and respiratory failure in Kaposi's sarcoma

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Massive hepatic necrosis in a child after administration of phenobarbital

A 2-yr-old child developed massive hepatic necrosis caused by an unusual hypersensitivity response to phenobarbital that was prescribed for presumed febrile seizures. Despite discontinuation of the barbiturate, this child experienced fulminant hepatic failure and died. Review of the literature indicates that phenobarbital-induced hepatic injury is uncommon and usually mild. Prompt and permanent cessation of the drug results in resolution of symptoms in most patients.

Differentiation of adenocarcinoma of the lung from mesothelioma. Periodic acid-Schiff, monoclonal antibodies B72.3, and Leu M1

The immunohistochemical reactivity of 38 mesotheliomas and 44 adeno-carcinomas or large cell carcinomas of the lung with monoclonal antibodies (MAb) B72.3 and Leu M1 was compared with their reactivity with the routine histochemic stains periodic acid-Schiff with diastase digestion (PAS-D) and alcian blue +/- hyaluronidase. Both MAbs reacted selectively with carcinomas when a positive test was set at greater than or equal to 10% reactive tumor cells. However, MAb B72.3 reacted with significantly more of the carcinomas (86%, chi-square test, P less than 0.01) and bound to a greater percentage of tumor cells (47 +/- 28%; mean +/- SD, t-test, P less than 0.001) than Leu M1 (57% and 25 +/- 28%, respectively). The similar reactivities of surgically resected tumor specimens and post mortem tissues with both antibodies confirmed antigen stability and suggested broad clinical utility. PAS-D stained 61% of the carcinomas. Using the markers for carcinomas (PAS-D, B72.3, and Leu M1), the tumors were classified into the correct group in 80 of 82 (98%) cases (95% confidence level: greater than 92% accuracy). The alcian blue stain was useful to confirm a diagnosis of dimorphic or epithelial mesothelioma (48% were positive).

Human immunodeficiency virus recovery from bronchoalveolar lavage fluid in patients with AIDS

We cultured bronchoalveolar lavage fluid for the human immunodeficiency virus (HIV) from 23 consecutive patients with acquired immunodeficiency syndrome (AIDS) and pulmonary symptoms. We also included a nonconsecutive AIDS patient with recent worsening of respiratory symptoms who had had lymphocytic interstitial pneumonitis (LIP) diagnosed six months earlier. Infectious HIV was present in the cellular fraction from two of the 23 consecutive patients and in the patient with LIP. No virus was isolated from the cell-free portion of the centrifuged fluids. The patients from whom HIV was cultured were not distinguishable from other patients by clinical, radiographic, or laboratory data, and their subsequent course did not appear to differ. One patient with a positive HIV culture had organizing pneumonia without evidence of LIP at autopsy three weeks after lavage. This study demonstrates that HIV can be cultured from cells obtained by bronchoalveolar lavage and suggests that its presence is not associated with a single specific pulmonary histologic pattern.

Endogenous peroxidase activity as a marker of macrophage renewal during BCG-induced inflammation in the rat lung

To determine whether the cytochemical localization of peroxidase activity could be used as a marker of monocyte influx into the lung during an inflammatory response, the authors studied the peroxidase phenotypes of lavaged alveolar macrophages from rats with bacille Calmette-Guérin (BCG)-induced pulmonary inflammation. Rats were immunized subcutaneously and 2 weeks later intravenously with BCG. During the early phase of pulmonary inflammation, an increase was observed in the numbers of alveolar macrophages with no peroxidase activity in the endoplasmic reticulum. These cells appeared to reflect monocyte influx into the injured lung. The later stages of inflammation were characterized by increased numbers of alveolar macrophages with peroxidase-positive endoplasmic reticulum, probably due to activation of enzymatic activity in situ. During the early phase, peroxidase activity was also observed within macrophage cytoplasmic inclusions, probably representing both primary monocyte lysosomes and internalized myeloperoxidase from inflammatory neutrophils. Serial observations indicated that the peroxidase-positive cytoplasmic inclusions became negative with time. It is concluded that inflammation-induced modulation of peroxidase activity in the endoplasmic reticulum and in cytoplasmic inclusions makes the alveolar macrophage peroxidase phenotype no more than a rough marker of monocyte influx into the inflamed lung.

Asbestos burden and the pathology of lung cancer

To determine whether we could distinguish asbestos-related lung cancers from unrelated ones, we typed and quantified by electron-optical methods the asbestos fibers in the lungs of 75 men with lung cancer. All but eight men had some history of asbestos exposure. On the basis of combined amosite and crocidolite (AC) concentrations, we divided the subjects into three groups (AC fibers per gram of dry lung): low (less than 10(5)); intermediate (10(5) to 10(6)); and high (greater than 10(6)). Age, smoking history, latent period, and type and location of tumors were similar in all three groups. Of 62 evaluated subjects, zero of 14 in the low group, seven of 29 in the intermediate group, and five of 19 in the high group had asbestosis. Epidemiologic studies suggest that persons exposed to concentrations of asbestos that can cause asbestosis are at increased risk for lung cancer. Thus, the subjects in our intermediate and high concentration groups may have been at increased risk for cancer, even when they did not have asbestosis. Because large burdens of asbestos do not always cause pulmonary fibrosis, asbestosis may be a poor marker of fiber-related lung cancer.

Numbers and types of asbestos fibers in subjects with pleural plaques

The authors analyzed asbestos fibers in lung samples from 20 subjects with pleural plaques discovered on autopsy and compared the findings to their previous analyses of lungs from subjects with little or no asbestos exposure and no plaques. Sixteen of the subjects with plaques had a history of exposure to asbestos. The authors used electron-optical methods and energy-dispersive x-ray spectroscopy to investigate the structure, diffraction patterns, and chemical composition of the asbestos fibers. The subjects with plaques had significantly higher median concentrations than the control subjects for amosite and crocidolite fibers (P less than 0.01) but not for the other fiber types. Minimal microscopic asbestosis was present in the 3 subjects who had the highest amosite concentrations. In the subjects with typical plaques, a history of asbestos exposure, and more fibers than in the control population, the relation of the plaques to asbestos was confirmed; for others, it was uncertain.

Fly ash lung: a new pneumoconiosis?

A laborer who worked in a steel mill and in a shipyard developed a nonspecific pulmonary interstitial fibrosis. Postmortem samples of his lung were digested, and the inorganic material present was extracted and examined using transmission electron microscopy, electron diffraction, and electron microprobe analysis. Uncoated asbestos fibers were present (1.4 X 10(5)/g wet lung), but the surprising finding was the presence of a large number of fly ash particles (6 X 10(6)/g wet lung). Fly ash, the particulate material produced during coal combustion, has not previously been reported to be present in human lung tissue. Although the contribution of the asbestos to this man's lung disease is uncertain, we believe, based on previous studies implicating aluminum silicates in pneumoconiosis, that the fly ash, an aluminum silicate, may be a contributing factor.

Severe pulmonary involvement in mixed connective tissue disease

Pulmonary involvement in mixed connective tissue disease has been considered a benign manifestation that is easily treated with corticosteroids. We followed 5 patients who had mixed connective tissue disease and severe, rapidly progressive, lung disease. Two types of lung disease were found, interstitial lung disease and pulmonary hypertension. Histologic sections from our patients were compared with sections from patients who had interstitial lung disease and systemic lupus erythematosus or pulmonary hypertension and scleroderma. Although clinical presentations were similar, the immunofluorescent and electron microscopic findings for interstitial lung disease were somewhat different in patients with systemic lupus erythematosus. Histologic findings for pulmonary hypertension appeared different in patients with mixed connective tissue disease and patients with scleroderma. For patients with either type of lung disease, corticosteroid therapy proved inadequate, but nearly cytotoxic therapy may be beneficial.

Asbestos and other ferruginous bodies: their formation and clinical significance

Analyses of asbestos bodies from the general population have confirmed that these structures, like asbestos bodies from the lungs of asbestos workers, contain an asbestos core. In members of the general population this core is almost always an amphibole, whereas asbestos workers may have bodies formed on either amphibole or chrysotile. Most adults have a few bodies, and increasing numbers are seen in blue collar workers and others who handle small amounts of the fiber, with the highest levels being seen in asbestos workers. In men with minimal or extensive occupational exposure, asbestos bodies are formed on the commercial fibers, amosite and crocidolite, whereas women also form a significant number of bodies on the noncommercial fibers, anthophyllite and tremolite. These findings suggest that women may be exposed to specific asbestos-containing products, eg, cosmetic talc. The commercial fibers found in women and white collar men probably reflect atmospheric pollution with asbestos. At the highest levels of exposure, numbers of asbestos bodies correlate in a general way with the presence of asbestosis, although no precise value has been determined above which asbestosis is always found. In persons with much lower or environmental exposure, there does not appear to be any correlation between numbers of bodies and disease, in particular between numbers of bodies and carcinoma of the lung or gastrointestinal tract. The situation for mesothelioma is uncertain.

Further observations on cytoplasmic hyaline in the lung

Cytoplasmic hyaline material resembling Mallory's alcoholic hyaline has previously been described in pulmonary alveolar cells of patients with asbestosis. We present 14 new cases of cytoplasmic hyaline found in patients with a variety of processes causing damage to the alveolar lining; these include cases of radiation pneumonia, diffuse interstitial fibrosis, organizing bacterial pneumonia, as well as asbestosis. Hyaline was found only in the setting of an unusual type II cell change, which ultrastructurally appeared to represent squamous metaplasia. We conclude that pulmonary cytoplasmic hyaline is not specific for asbestosis but rather is a nonspecific reaction to injury;

Analysis of the cores of asbestos bodies from members of the general population: patients with probable low-degree exposure to asbestos

Asbestos bodies were isolated from the lungs of 21 patients who had 300 to 9,000 of such bodies/g of lung tissue, a concentration frequently found in manual laborers in the general population who are not primary asbestos workers. All of the 123 bodies examined by electron diffraction produced diffraction patterns consistent with amphibole varieties of asbestos. Electron microprobe analysis (energy dispersive x-ray spectroscopy) of 46 bodies revealed that 38 of the cores were composed of the commercial amphiboles, amosite and crocidolite, whereas only 8 were composed of the noncommercial amphiboles, anthophyllite and tremolite. Review of the occupations of these patients revealed that all but one had blue-collar jobs. For many of these persons, putative sources of asbestos exposure such as construction work could be defined, but for some, the source could not be determined. One woman was apparently exposed to asbestos in the practice of her hobby of ceramics, in which she used anthophyllite-contaminated clay. We concluded that commercial amosite/crocidolite asbestos forms the cores of most asbestos bodies in manual laborers in the general population and that the source is usually occupational.

Numbers of asbestos bodies in urban patients with lung cancer and gastrointestinal cancer and in matched controls

We compared the numbers of asbestos bodies extracted from the lungs of 103 patients with lung cancer and 50 patients with gastrointestinal malignant neoplasms to the numbers of bodies extracted from lungs of control patients matched for age, sex, smoking habits, and, in some cases, occupation. All patients were urban dwellers over the age of 40 years, and none was a primary asbestos worker. No differences in the counts of asbestos bodies were observed between the tested and control populations. The numbers of asbestos bodies did correlate well with occupation; the highest counts were found in male manual laborers. We conclude that in the urban population studied herein, the numbers of asbestos bodies alone do not correlate with the presence of pulmonary or gastrointestinal carcinoma; however, uncoated asbestos fibers are also known to be present in the lung, and the possibility that such tumors may be related to the numbers of these fibers in lungs remains to be explored.

Analysis of the cores of ferruginous (asbestos) bodies from the general population. III. Patients with environmental exposure

Typical asbestos bodies visible by light microscopy were isolated from the lungs of 29 persons with fewer than 100 such bodies per gram of lung, a level that is considered indicative of environmental rather than occupational asbestos exposure. Of 144 bodies examined by electron diffraction, 143 contained an amphibole asbestos core and one contained a chrysotile asbestos core. Thirty-five bodies from 21 patients were also analyzed by electron microprobe. Of these, 21 were chemically consistent with amosite or crocidolite asbestos, 13 with anthophyllite asbestos, and one with tremolite asbestos. Certain differences in chemical fiber types between men and women became apparent. Although cores of amosite and crocidolite predominated in men (12 of 14, 86 per cent), anthophyllite and tremolite comprised 57 per cent (12 of 21) of the cores found in women, a statistically significant difference. These differences suggest that the major commerical varieties of amphibole asbestos (amosite and crocidolite) are the source of the fibers in men, whereas in women a major source may be cosmetic talc, which is often contaminated with anthophyllite and tremolite. On the basis of this study and our previous studies, we conclude that almost all typical asbestos bodies from the lungs of the general population contain an amphibole asbestos core.

Correlation of quantitative asbestos body counts and occupation in urban patients

Asbestos bodies were quantified in digests of lung from 252 urban patients who were over 40 years of age. Patients were assigned to six occupational categories that had been determined without knowledge of asbestos body counts. Asbestos bodies were present in the lungs of 96% of the total population. Fewer than 12% of the white-collar men and the blue- and white-collar women had more than 100 asbestos bodies per gram of lung, whereas 32% of the blue-collar men not working in steel mills or construction, 45% of steelworkers, and 65% of construction workers had more than 100 asbestos bodies per gram lung. This distribution suggests that almost everyone in our population has some exposure to asbestos, and certain persons are subject to an additional occupational exposure. Whether asbestos bodies in low concentration are related to disease remains to be determined.

The significance of pulmonary changes associated with cerebral perfusion with hypoxic blood in monkeys

Parameters of cerebral and pulmonary function were studied in ten animals whose brains were perfused with hypoxic right atrial blood according to the Moss method. All animals died as a result of cerebral hypoxia at about 95 minutes after the onset of perfusion. Gross pulmonary congestion, edema, and leukocyte plugs occurred in the seven animals breathing spontaneously, but positive pressure ventilation prevented these changes in three. The resumption of cerebral perfusion with oxygenated blood after 30 minutes of the Moss procedure did not prevent the pulmonary changes and, of more importance, did not prevent cerebral swelling and death at about the same time as that of all the other animals. There were no changes in oxygen uptake or in arterial oxygen tension to indicate that progressive pulmonary failure contributed to death. It is concluded that this model produces brain swelling and brain death with incidental pulmonary pathological changes indistinguishable from early findings in hemorrhagic shock models and that the cerebral hypoxic perfusion model in monkeys is not suitable for studying the effects of "shock lung" therapy.

A simple method for preparing ferruginous bodies for electron microscopic examination

A new method of preparing ferruginous (asbestos) bodies for electron-optical examination is described. Pulmonary tissue is dissolved in bleach and the residue collected on a Millipore filter. The ferruginous bodies are localized by light microscopy, and a portion of the filter containing a body is cut out and mounted on a coated electron microscope grid. The filter is dissolved in acetone vapor in a condensation washer, leaving the bodies, as well as uncoated submicroscopic fibers, on the grid. This method can be used to obtain bodies from the lungs of individuals after all degress of asbestos exposure, but it is particularly useful when dealing with minimally exposed or non-exposed individuals whose lungs contain very few bodies. The procedure allows easy identification of body cores by electron diffraction or electron microprobe analysis.

Analysis of the cores of ferruginous (asbestos) bodies from the general population. I. Patients with and without lung cancer

Ferruginous (asbestos) bodies may be found in the lungs of almost everyone in the population, but little information is available as to whether such bodies are nucleated on asbestos or on some other fibrous dust. In this study morphologically "typical" ferruginous bodies were isolated from the lungs of 23 autopsy and surgical patients, none of whom had primary asbestos exposure. Eleven patients had carcinoma of the lung. To determine the nature of the core, 328 bodies were examined by electron diffraction. Of these, 264 (80%) showed the diffraction patterns of amphibole asbestos, whereas six showed the pattern of chrysotile asbestos. No amorphous cores or crystalline nonasbestos cores were identified. Fifty-eight (18%) bodies could not be diffracted because of the thickness of the iron-protein coat. No differences were seen between patients with and without lung cancer. We conclude that typical ferruginous bodies have asbestos cores, which are usually amphibole type. The findings suggest widespread exposure to asbestos dust; occupational histories appeared to indicate the source of exposure in some but not all patients.

Changes with age in muscular pulmonary arteries

The mean wall thickness, in relation to the external diameter, of 100 muscular arteries distended by barium gelatin at 100cm H2O pressure was calculated in "normal" lungs from patients who ranged in age from 3 to 79 years. For normal vessels less than 2 mm in diameter the mean was 2.4% of the external diameter. The mean for vessels in the five persons under 40 years was 1.8% but it was 2.8% for the five older individuals. Although this difference may reflect some increased muscularity with age, some of the increment may be related to a reduced distensibility of vessels caused by the accumulation of interstitial fluid, as manifested by increased weight in the older lungs. Intimal fibrosis was found to increase with age but occurred in less than 50% of the vessels measured.

Muscular pulmonary arteries in chronic obstructive lung disease

The small muscular pulmonary arteries are thought to be normal in obstructive pulmonary disease despite prolonged hypoxic stimulation to medial thickening. Because measurements on nondistended vessels have considerable variability, we reinvestigated the problem by studying the percentage of wall thickness of distended arteries in lungs taken post mortem from 5 asymptomatic emphysematous patients and 11 symptomatic patients with obstructive pulmonary disease. Vessels in the former patients had normal medial thicknesses. In contrast, we found an elevated mean percentage of wall thickness for vessels between 0.3 and 2.0 mm in diameter of 4.46% +/-1.44% (mean +/-SD) for patients with obstructive airways disease. Obstructive pulmonary disease, therefore, produced medial hypertrophy in small muscular arteries similar to that seen in other conditions associated with chronic hypoxia.

Pulmonary tumorlet. A form of peripheral carcinoid

Twenty cases of pulmonary tumorlet are presented. Approximately one-third of the tumors occurred in lungs severely scarred by bronchiectasis or other inflammatory processes; the other two-thirds were found in lungs with little to no scarring. In the former instances, tumorlets were found in large scars in which identifying architectural features had been destroyed. In the latter, the tumorlets were seen in minute fibrous nodules, surrounding or obliterating small bronchi or bronchioles. Argyrophilic granules were demonstrated in 14 of 15 cases; in the electron microscope these were consistent with neurosecretory granules. Their location, silver staining properties, and ultrastructure suggest that pulmonary tumorlets are minute peripheral carcinoid tumors.

So-called "minute pulmonary chemodectoma": a tumor not related to paragangliomas

Twenty-six cases of so-called "minute pulmonary chemodectoma" are presented. The patient population showed a marked female preponderance, and there appeared to be an association of the lesion with pulmonary injury from a variety of causes including cardiac failure, chronic bronchitis and emphysema, and thromboemboli. Half the cases had multiple tumors. Microscopically, the tumors consisted of nests of cells in the interstitial tissue near small veins. Argentaffin and argyrophil stains failed to demonstrate cytoplasmic granules in any case. By electron microscopy, the nests were composed of large cells with broadly interdigitating processes connected by many well-formed desmosomes. The cytoplasm was filled with numerous 60-A filaments. The Golgi apparatus was prominent, while other organelles were sparse. No secretory granules were identified. It is concluded that the fine structure and lack of silver-positive granules are inconsistent with the morphology of previously reported paragangliomas, but that there is a resemblance at the light and electron microscopic level to meningeal arachnoed cells and the cells of meningiomas.

Pulmonary tumorlet. A form of peripheral carcinoid

Twenty cases of pulmonary tumorlet are presented. Approximately one-third of the tumors occurred in lungs severely scarred by bronchiectasis or other inflammatory processes; the other two-thirds were found in lungs with little to no scarring. In the former instances, tumorlets were found in large scars in which identifying architectural features had been destroyed. In the latter, the tumorlets were seen in minute fibrous nodules, surrounding or obliterating small bronchi or bronchioles. Argyrophilic granules were demonstrated in 14 of 15 cases; in the electron microscope these were consistent with neurosecretory granules. Their location, silver staining properties, and ultrastructure suggest that pulmonary tumorlets are minute peripheral carcinoid tumors.

Association of asbestos and bronchogenic carcinoma in a population with low asbestos exposure

Quantitative counts of ferruginous bodies were performed on digests of lungs from 100 control and 30 lung cancer patients. It was found that the lung cancer group had significantly higher levels, although only 1 patient was known to be occupationally exposed to asbestos. It is suggested that even extremely low levels of asbestos exposure may have a carcinogenic effect.