Neutrophils and asthma

The importance of inflammation in asthma has been recognized for a long time and recently proved in man and animal models. All inflammatory cells are probably involved in exacerbations of asthma. Neutrophils in particular are present in the airways during and after the spontaneous asthma attacks in man and during asthmatic reactions and airway hyperresponsiveness induced experimentally in man and animals. Depletion of neutrophils prevents these effects and repletion with neutrophils reconstitutes them. Moreover, the supernatant from stimulated human neutrophils causes transient hyperresponsiveness. However, neutrophils are not increased in stable asthmatics with hyperreactive airways and are not involved in airway hyperresponsiveness induced experimentally in some animals (e.g. guinea-pigs). The studies reviewed suggest that neutrophils may be involved in the transient increases of airway responsiveness associated with exacerbations of asthma, but not in the long-lasting hyperresponsiveness of stable asthmatics.

Circulating factors that modify lung cell DNA synthesis following exposure to inhaled oxidants. I. Effect of serum and lavage on lung fibroblasts following exposure of adult rats to 1 ppm ozone

Adult rats were exposed to 1 ppm (1.96 mg/m3) ozone or air for 2 wk. Animals were sacrificed at 3, 5, 7, or 14 d after the onset of exposure, and samples of plasma and lung lavage were obtained. Heat-inactivated plasma, from animals exposed to ozone for 7 or 14 d, significantly increased DNA synthesis by lung fibroblasts compared with plasma from air-exposed animals. Fractionation of plasma and lavage samples indicated that the factor responsible had an isoelectric point of 6.45-6.75 and a molecular weight of 32 +/- 2 kDa. This factor has a dose-dependent effect on lung fibroblast DNA synthesis in culture, but no significant effect on cultured pneumocyte DNA synthesis. The factor is detectable within 72 h of exposure, and may hold some promise as a marker of early oxidant lung injury.

Alveolar macrophages from patients with asbestos exposure release increased levels of leukotriene B4

The alveolar influx and subsequent activation of inflammatory cells such as neutrophils and eosinophils are believed to be important in the pathogenesis of many interstitial lung disorders, including asbestosis. Indices of lower respiratory tract abnormalities detected by bronchoalveolar lavage (BAL) were investigated in 93 asbestos-exposed workers as well as in smoking (n = 12) and nonsmoking (n = 10) control subjects. Patients with clinical asbestosis (n = 12) exhibited increases in both BAL neutrophils and BAL eosinophils, expressed as both percentage of total cells and total numbers, when compared to asbestos-exposed workers without asbestosis (n = 81) and control subjects. Significantly greater numbers of BAL neutrophils were also found in asbestos-exposed workers without asbestosis than in either smoking or nonsmoking control subjects. These abnormalities correlated significantly with in vitro BAL alveolar macrophage production of the potent leukocyte chemotaxin, leukotriene B4 (LTB4). For example, basal, unstimulated LTB4 production was 3.1 +/- 0.8 ng/10(6) alveolar macrophages for patients with asbestosis, 1.05 +/- 0.2 ng/10(6) cells in asbestos workers without asbestosis, 0.9 +/- 0.2 ng/10(6) cells in control nonsmokers, and 0.2 +/- 0.05 ng/10(6) cells in control smokers. Stimulated LTB4 release from BAL alveolar macrophages (A23187 or arachidonate) was even more pronounced in asbestos workers with or without asbestosis, suggesting an in vivo priming effect on alveolar macrophage synthesis of LTB4. Cell-free BAL supernatants from asbestos-exposed patients with or without asbestosis also contained significantly greater amounts of LTB4 than did those from control subjects, indicating enhanced in vivo production of this inflammatory mediator.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of vitamin E levels in plasma, bronchoalveolar lavage, and lung tissues of adult pulmonary patients

Plasma, bronchoalveolar lavage fluids (BAL), and lung parenchyma were analyzed for vitamin E and polyunsaturated fatty acid (PUFA) concentrations in three groups of patients routinely receiving oxygen therapy--two with adult respiratory distress syndrome (ARDS and SARDS), a third with pneumonia (PNEU), as well as a fourth group of patients receiving little or no oxygen therapy (OTHER). Only plasma alpha- and gamma-tocopherols were significantly lower in patients receiving oxygen therapy compared to those not requiring oxygen. Among diagnosis groups, PNEU patients exhibited highest levels of alpha-tocopherol in BAL, though all groups on oxygen had greater amounts of alpha-tocopheryl quinone in BAL as compared to those of the OTHER group. No significant differences in BAL measures were observed between oxygen and non-oxygen groups, however. No statistical tests on lung measures could be performed between these groups because of insufficient sampling for the OTHER group. A highly significant relationship was observed (r = +0.73, p less than 0.004) between plasma vitamin E and lung vitamin E when expressed in terms of PUFA, whereas no significant relationship was observed if plasma vitamin E and lung vitamin E levels were compared directly. No relationship was obtained for BAL alpha-tocopherol (expressed per number of cells) and lung alpha-tocopherol. These findings support previous reports that in an appropriate setting plasma vitamin E:PUFA ratios along with smoking status may be used to evaluate lung vitamin E levels when also expressed in terms of PUFA.

[Products of lipid peroxidation in the blood and respiratory secretions in 3 patients with acute respiratory diseases]

Oxygen free radicals have been suggested to be involved in ARDS pathogenesis. Their production may be caused by leukocyte activation and by administration of high oxygen concentrations. Radicals can oxidize lipids with production of dienes. In order to gather an indirect proof of radical production, dienes were repeatedly assessed in plasma and bronchoalveolar lavage (BAL) samples from three patients affected by ARDS. Plasma levels resulted higher than normal ones in all the patients initially; concentrations in BAL samples were lower than in plasma. Successively dienes decreased progressively in the patient who survived, whereas an increase was observed in BAL samples from the other patients, who died. The last trend was accompanied by a smaller increase in plasma levels.

Biochemical study of protease inhibitors in normal chinchilla middle ear

Protein concentration and inhibitory capacity of both alpha 1-antitrypsin (alpha 1-AT) and alpha 2-macroglobulin (alpha 2-M) were measured in plasma and middle ear bulla (MEB) washings of chinchillas by use of specific antisera against chinchilla alpha 1-AT and alpha 2-M. Low molecular weight (LMW) trypsin inhibitor also was analyzed in MEB washings. Chinchilla alpha 2-M showed a common antigenicity with human alpha 2-M. The mean value of alpha 1-AT in chinchilla plasma was 412.0 +/- 87.8 and that of alpha 2-M was 435.0 +/- 117.1 mg/dL. There was a significant relationship between alpha 1-AT level and antitryptic activity, and between alpha 2-M level and trypsin binding activity in plasma. The majority of alpha 1-AT and alpha 2-M in plasma is present as free inhibitors unsaturated with proteases. The MEB washings had significant antitryptic activity, which is attributed to both alpha 1-AT and LMW trypsin inhibitors. Inhibitory functions of alpha 1-AT and LMW trypsin inhibitors appear to play an important role in the defense of the normal middle ear mucosa.

Development of chronic airway hyperresponsiveness in ragweed-sensitized dogs

We studied dogs neonatally sensitized to ragweed and their littermate controls at 4, 6, 8, 10, 12, and 15 mo of age. Acute allergic airway response to inhalation of ragweed in the sensitized dogs was marked (greater than 12-fold increase from base line) and reproducible at all times. Nonallergic airway responsiveness, measured as the concentration of acetylcholine required to increase airway resistance by 5 cmH2O.l-1.s (PC5), increased in sensitized and decreased in nonsensitized dogs from 4 to 15 mo of age (P less than 0.01). Before antigen, at 12 and 15 mo, sensitized dogs were significantly (P less than 0.05) more responsive to acetylcholine than controls. Six hours after antigen, sensitized dogs were 11-fold more responsive (P less than 0.005) than controls at those times. More eosinophils and mast cells and fewer macrophages (P less than 0.05) were present in bronchoalveolar lavage (BAL) from 12- and 15-mo-old sensitized dogs than their controls. BAL fluid histamine was higher (P less than 0.05) in sensitized than control dogs. Regression analysis revealed r = -0.75 (P = 0.003) between BAL mast cells and PC5 in sensitized dogs and R2 = 0.89 for PC5 and BAL mast cells, macrophages, and eosinophils. Neonatally sensitized dogs represent an excellent animal model in which to study the pathophysiology of asthma.

Prostaglandin E2 in the lung lavage fluid of premature newborns before and after surgical or medical closure of a patent ductus arteriosus

To analyze the role of prostaglandin E2 in maintaining ductal patency in premature newborns, we measured the PGE2 concentration in the lung lavage fluid of nine patients within 24 h before and 4-8 h after surgical ligation of a patent ductus arteriosus and in two patients before and after closure of the ductus following intravenous indomethacin. The concentration of PGE2 ranged from 240 to 3770 pg/ml (mean 1666 +/- 1256 pg/ml) before operative intervention and show a significant decrease to 0-300 pg/ml (mean 93 +/- 106 pg/ml, P less than 0.001, Student's two-tailed t-test) within a few hours after ligation of the ductus arteriosus. The same significant decrease could be seen in two patients with successful indomethacin therapy (0.25 mg/kg in three doses/day) with concomitant ductus closure. In contrast, when indomethacin was given in a reduced dose (0.1 mg/kg in three doses/day), only a slight effect on PGE2 synthesis could be seen without closure of ductus arteriosus. We suggest that the fall of PGE2 levels in lung lavage fluid reflects the local synthesis in the ductus arteriosus itself and is responsible for the decrease induced by surgical ligation or pharmacological inhibition by indomethacin.

Bronchoalveolar lavage T-cell and Ia antigen quantitation by flow cytometry in acute and chronic experimental hypersensitivity pneumonitis

Increasing evidence implicates effector T-cells in the pathogenesis of hypersensitivity pneumonitis. We utilized T-cell- and Ia-specific antibodies, flow cytometry, and computer analysis to quantitate T-cell numbers and Ia expression on lung cells of established rabbit models of acute and chronic hypersensitivity pneumonitis (HSP). We used analysis of variance (ANOVA) and Turkey's follow-up to evaluate group differences. In the acute HSP group, increased percentages of T-cells and greater Ia expression were present on bronchoalveolar lavage (BAL) cells at 24 h after inhalational allergen challenge. Increased BAL T-cell numbers were found in the chronic HSP group produced by repeated inhalation of antigen and muramyl dipeptide, compared to "desensitized" animals and control groups. Both chronic HSP and desensitized groups demonstrated increased Ia expression on BAL cells. Pathology scores for individual animals in both acute and chronic protocols correlated significantly (Pearson correlation coefficients) with total numbers of BAL cells, percentages of T-cells, and percentages of Ia-positive cells recovered. Findings are consistent with the hypothesis that cell-mediated hypersensitivity is a central mechanism in the pathogenesis of experimental hypersensitivity pneumonitis.

Neutrophil chemotactic factors in bacterial pneumonia

The influx of neutrophils into the lung is a prominent feature in patients with bacterial pneumonia. Since neutrophils migrate in response to chemotactic factors, chemotactic activity was evaluated in bronchoalveolar lavage (BAL) fluid obtained from 12 patients with bacterial pneumonia and ten normal control subjects. Chemotactic activity was greatly elevated in the BAL fluid of the pneumonia patients compared with control subjects (p less than 0.01). To partially characterize the chemotactic factors present in the lavage fluid of the patient group, molecular sieve chromatography was performed on the lavage fluid, and at least three peaks of chemotactic activity were identified. Since the molecular weight of the smaller peaks approximated the molecular weight of two known chemotactic factors, C5a and leukotriene B4, these factors were measured in lavage fluid by radioimmunoassay. C5a was detectable in none of the normal subjects but was detectable in four of 14 BAL samples obtained from the patients. Leukotriene B4 was detectable in all subjects and was significantly elevated in the pneumonia patients (552 +/- 95 vs 81 +/- 16 pg/ml, p less than 0.01). These findings demonstrate that elevated neutrophil chemotactic activity is present in the lungs of patients with bacterial pneumonia and suggest that C5a and leukotriene B4 may account, at least in part, for this increase.

Use of segmental airway lavage to obtain relevant mediators from the lungs of asthmatic and control subjects

Studies have demonstrated that increased amounts of histamine in the airways of asthmatic patients are associated with increased airway reactivity. However, using routine bronchoalveolar lavage (BAL), histamine can be detected in only a portion of asthmatic subjects and a minority of control populations. To obtain relevant mediators from the airways in higher concentrations by avoiding the dilution inherent with a standard BAL, a technique was developed to lavage isolated airway segments of the human lung that employed a double-lumen bronchoscope and a balloon-tipped catheter. Lavage fluid obtained by this method yielded significantly higher concentrations of histamine than that obtained with routine BAL (asthmatic subjects, 2,403 +/- 633 pg/ml vs 188 +/- 42 pg/ml; rhinitis subjects, 533 +/- 187 pg/ml vs 113 +/- 53 pg/ml; normal subjects, 174 +/- 63 pg/ml vs 11 +/- 11 pg/ml). Similar findings were also noted for prostaglandin D2 (PGD2). Segmental airway lavage also resulted in higher lavage fluid concentrations of LTB, than routine BAL. Segmental airway lavage should help in studying the relationship of mast cell degranulation to airways reactivity in both asthmatic and other study populations.

Inhibition of human bronchial kallikrein in asthma

Human bronchial kallikrein (HBK) is the major kinin-generating enzyme in the airways of asthmatic subjects. We examined the in vitro inhibition of HBK and its in vivo regulation in asthma. HBK kininogenase activity was measured by cleavage of radiolabeled purified high molecular weight kininogen (HMWK) (125I HMWK). Functional inhibition of the enzyme was present after co-incubation with either normal human plasma (NHP) or preparations of alpha-1-proteinase inhibitor (alpha 1-PI). Stable HBK inhibitor complex was detected at 92 K by immunoblotting employing anti-HUK as a probe. Anti alpha 1-PI probes did not demonstrate the 92 K complex under identical conditions, raising the possibility of an additional co-purifying protein involved in HBK binding. alpha 1-PI antigenic and activity levels were measured in asthmatic bronchoalveolar lavage (BAL) fluid. In only a single sample of the six examined was alpha 1-PI activity detected. In two of the remaining five samples, low levels of alpha 1-PI antigen were present which were functionally inactive. In the BAL fluid containing alpha 1-PI activity, progressive functional inhibition of kininogenase activity correlating with HBK inhibitor complex formation occurred during BAL fluid incubation. In contrast, BAL fluid lacking alpha 1-PI activity failed to show progressive kininogenase inhibition or complex formation under identical conditions. In all experiments, the time course of HBK inhibitor interaction was markedly prolonged, requiring 150-min co-incubation with either NHP or the alpha 1-PI preparation for greater than 80% inhibition of function and near maximal complex formation. The slow rate of inhibition of HBK may allow for its continued activity and kinin generation in the airways of asthmatic subjects.

Clinical and subclinical alveolitis in collagen vascular diseases: contribution of alpha 2-macroglobulin levels in BAL fluid

The probability that patients with collagen vascular diseases (CVD) will develop fibrosis is unpredictable. Since changes in bronchoalveolar lavage (BAL) cell data can be observed in CVD patients without evidence of lung involvement, we investigated whether the study of soluble components in BAL could help to distinguish CVD patients with lung involvement (n = 15) from those without pulmonary disease (n = 37). Our results demonstrate that the alveolitis observed in patients with overt lung involvement is associated with an increase of BAL alpha 2-macroglobulin (alpha 2-MA). In contrast, the BAL alpha 2-MA levels were found to be normal in CVD patients without evidence of pulmonary disease as well as in CVD patients with overt lung involvement treated with steroids. This was observed even in the presence of high neutrophil or lymphocyte counts in BAL. In conclusion, when neutrophils or lymphocytes accumulate in the lungs of CVD patients without evidence of lung damage, in the majority of patients this cell accumulation is not associated with an increase of BAL soluble components.

Effects of repeated inhalation exposures to 1-nitropyrene, benzo[a]pyrene, Ga2O3 particles, and SO2 alone and in combinations on particle clearance, bronchoalveolar lavage fluid composition, and histopathology

The toxicities of 1-nitropyrene (NP) and benzo[a]pyrene (BaP), inhaled alone and in combination with particles and an irritant gas, were examined to evaluate synergisms among the organic compounds, particles, and gas. Groups of F344 rats were exposed 2 h/d, 5 d/wk for 4 wk to atmospheres of pure NP aerosol (7.5 mg/m3), and to these same compounds adsorbed to Ga2O3 particles (27 mg/m3) both with and without coexposure to 5 ppm SO2. Rats were also exposed to Ga2O3 and SO2 alone. Measurements were made of lung burdens of Ga2O3 particles and retention of radiolabeled tracer particles after the cessation of exposure to evaluate effects on particle clearance. Bronchoalveolar lavage fluid was analyzed to assess inflammation and cytotoxicity. Histopathology was examined to assess the nature and extent of lung injury. Particle clearance was significantly impaired (p less than .05) in all groups whose exposure atmosphere included Ga2O3, but was not significantly changed in the other exposure groups.

Effect of oxygen exposure on ATP content of rat bronchoalveolar lavage

Exogenous ATP stimulates surfactant phospholipid secretion in vitro through binding to P2-purinoceptors on the surface of the alveolar type II cell. To determine whether ATP is present in the bronchoalveolar space at concentrations sufficient to stimulate phospholipid secretion, we determined bronchoalveolar lavage ATP content in rats exposed to different inspired oxygen concentrations. Bronchoalveolar lavage ATP content of control animals exposed to room air was 155 +/- 12 nmol ATP/lavage (n = 17) and fell in a dose-dependent fashion to 34 +/- 5 nmol ATP/lavage in animals exposed to 85% oxygen for 72 h (n = 17). Airway content of ATP metabolites fell in a similar fashion in response to oxygen exposure. The decrease in airway ATP content after oxygen exposure was also time-dependent. ATP content in young adult male rats exposed to 85% oxygen decreased from a mean of 236 nmol ATP/lavage on d 1 of exposure to 18 nmol ATP/lavage after 4 d. There was no further decrease in bronchoalveolar lavage ATP content after 4-7 d of oxygen exposure. Despite the fall in airway levels of ATP, disaturated phosphatidylcholine levels increased. Rat bronchoalveolar lavage contained measurable concentrations of ATP, indicating the presence of ATP in the airway at levels which modulate surfactant phospholipid secretion from isolated alveolar type II cells in vitro. Bronchoalveolar lavage ATP content decreased significantly with exposure to oxygen, whereas disaturated phosphatidylcholine content increased.

Influenza virus-specific T cells lead to early interferon gamma in lungs of infected hosts: development of a sensitive radioimmunoassay

A sensitive immunoradiometric assay for murine interferon gamma (MuIFN-gamma) has been developed and used reproducibly to measure low levels of MuIFN-gamma in lung lavage samples from influenza-infected mice. In control infected mice, IFN-gamma peaked on day 6, but transfer of virus-specific cytotoxic T cells or T helper cells, which reduced virus replication in vivo in infected hosts, resulted in an earlier peak on day 4.

Effects of paraquat on canine bronchoalveolar lavage fluid

Bronchoalveolar lavage (BAL) recovers the epithelial lung fluid of the lower respiratory tract. In this study, we have used BAL to detect early pulmonary injury in beagle dogs following an intravenous infusion of 10 mg paraquat dichloride/kg bodyweight. Bronchoalveolar lavage was performed twice in 11 dogs, 60 hr before and 34 hr after an intravenous infusion of paraquat dichloride (n = 8) or saline (n = 3). The dogs were studied in three groups: (1) paraquat only (n = 4); (2) paraquat plus hemoperfusion (n = 4); and (3) hemoperfusion only (n = 3). Because hemoperfusion, a treatment used for paraquat poisoning, could have effects on BAL independent of paraquat, we evaluated the effects on BAL fluid of this procedure performed separately from and together with administration of paraquat. We examined cytology, proteins, enzymes, and glutathione in the BAL fluid and expressed all results per milliliter of aspirated lavage fluid. Hemoperfusion did not alter the BAL fluid. In contrast, in dogs studied 34 hr after administration of paraquat, total cell counts, alveolar macrophage and neutrophil counts, and concentrations of total protein, albumin, ACE, LDH, and ALP were increased. Bronchoalveolar lavage in the dog provides an excellent tool with which to detect early paraquat-induced pulmonary injury. The same technique could be useful for sequential monitoring of other types of pulmonary disease and injury.

Recovery of treatment doses of surfactants from the lungs and vascular compartments of mechanically ventilated premature rabbits

Premature rabbits delivered by cesarean section at 28 d of gestation were each given intratracheally 75 mg/kg of radiolabeled preparation of either natural rabbit surfactant, natural calf surfactant, or surfactant-TA. Each newborn rabbit was ventilated for up to 6 h in a ventilator-plethysmograph with individual adjustments of peak inspiratory pressures to attain tidal vol of 12-15 mL/kg body wt. Dynamic compliances were about 0.7-0.9 mL/cm H2O. kg after treatment with the three surfactants and did not deteriorate during the 6-h study. Rabbits were randomly studied at 0.5, 1.5, 3, 4.5, and 6 h of age for the recovery of the labeled surfactant phosphatidylcholine in the total lungs (alveolar wash plus postlavage lung tissue). The labeled phosphatidylcholine was cleared from the total lungs of rabbits treated with natural rabbit or calf surfactants at comparable rates of about 25%/6 h. In contrast, the clearance rate of surfactant-TA phosphatidylcholine from the total lungs was not significantly different from 0. Lipids from rabbit surfactant that had been administered intratracheally were only minimally present in the blood and liver. In other similarly treated rabbits, the lipids from radiolabeled rabbit surfactant and liposomes of dipalmitoylphosphatidylcholine that had been injected intravenously were recovered in blood and liver in substantial quantities. These studies documented significant losses of rabbit and calf surfactant phosphatidylcholine but not surfactant-TA phosphatidylcholine from the lungs of preterm ventilated rabbits. The losses were not explained by surfactant losses to the vascular compartment.

Prostaglandin E1 infusion fails to prevent hyperoxic lung injury in adult rabbits

Arachidonic acid (AA) metabolites may be important mediators in the hyperoxic lung injury process. We have previously demonstrated, in an adult model of hyperoxic lung injury, that bronchoalveolar lavage (BAL) fluid levels of AA metabolites of the cyclooxygenase pathway increase before evidence of overt injury. Nonselective inhibition with indomethacin or dexamethasone failed to ameliorate the injury process, possibly because production of prostaglandin I2 (PGI2) was suppressed. In this study, we attempted to ameliorate hyperoxic lung injury using an infusion of prostaglandin E1 (PGE1), since PGE1 has some of the potentially protective effects of PGI2. Thirty-two adult rabbits were exposed to greater than 95% oxygen; eight served as controls and 24 received PGE1 infusion (five, nine, and ten received 0.1, 0.06, and 0.03 micrograms/kg.min, respectively). At the end of the 65-h exposure period, BAL of the left lung was performed; the right was saved for light microscopy. PGE1 infusion at the 0.06 and 0.03-micrograms/kg.min doses resulted in significantly fewer polymorphonuclear leukocytes (PMN) in BAL fluid (p less than .05). However, PGE1 infusion did not significantly ameliorate the lung injury process. In summary, although PGE1 infusion inhibited the influx of PMN into the lung, treatment did not result in any significant amelioration of the hyperoxic lung injury process.

Cellular and humoral observations in a patient with allergic bronchopulmonary aspergillosis during a nonasthmatic exacerbation

A patient is described with an asymptomatic exacerbation of allergic bronchopulmonary aspergillosis (ABPA), clinically characterized by pulmonary infiltrates, with absence of obstructive reactions and a short period of hemoptysis 2 weeks before hospitalization. Cell counts and antibody concentrations were measured in serum, and bronchoalveolar fluid (BAF) samples and values were compared with data from previous periods of symptomatic exacerbations. During the asymptomatic exacerbation, concentrations of antibody to Aspergillus fumigatus, total IgE, and precipitating antibodies were elevated in peripheral blood. No quantitative differences in specific antibody concentrations (IgE, IgG, IgA, and IgM) against A. fumigatus were found between sera from symptomatic and asymptomatic periods of ABPA. In contrast to observations in the serum, protein concentrations in BAL fluid were normal during the asymptomatic period, whereas high concentrations were found during the symptomatic phases. Local antibody concentrations (in BAF) were characterized by high levels of IgA antibodies against A. fumigatus. During asymptomatic and symptomatic phases, eosinophils were elevated in peripheral blood, in sputum, in BAF, and highly elevated in tissue biopsy specimens. Activated eosinophils were found, as indicated by the presence of light-density cells in the circulation and monoclonal antieosinophil cationic protein binding to bronchoalveolar lavage eosinophils. In contrast to the symptomatic phase of ABPA in 1980, demonstrating aspecific airway reactivity to several pharmacologically active substances, no such hyperreactivity was found during the asymptomatic phase of ABPA in 1986. It is proposed that the asymptomatic infiltrative phase of ABPA is an intermediate stage that can develop into a symptomatic phase after prolonged and intensified infiltration of eosinophils. Mediators from the inflammatory cells may be involved in the induction of bronchial hyperresponsiveness. After induction of this hyperreactive stage of the airways, additional liberation of mediators from either eosinophils and/or mast cells will lead to a symptomatic (obstructive) phase of ABPA.

[Allergen-induced late bronchoconstriction and airway hyperresponsiveness in guinea pigs]

Allergen-induced bronchoconstrictive responses were examined in a guinea pig model actively sensitized by the inhalation of aerosolized ovalbumin (OA), which showed reproducible late bronchial responses (LBR). OA-challenge was performed under cover of mepyramine through the inhaled route in spontaneous breathing without anesthesia. The respiratory resistance (Rrs) was measured by the oscillation method for 96 h after OA challenge. All of the 22 guinea pigs displayed immediate bronchial responses (IBR), followed by 2 or 3 phase LBR that peaked at 6-8 h and 24 h after OA challenge. Examination of bronchoalveolar lavage fluid (BALF) revealed a significant increase in neutrophils at 1 h (p less than 0.01) and eosinophils at 7 h and 96 h (each p less than 0.01) after OA challenge. OA-challenge induced airway hyperresponsiveness to histamine (p less than 0.01) at 96 h that was associated with a significant increase in eosinophils (p less than 0.01) in BALF compared with lavages at 7 h. Intravenous administration of 1% OA induced a significant increase of leukotriene (LT)B4, C4, D4 in tracheal lavage fluids at IBR phase in each control (p less than 0.01). The increases of Rrs in LBR were inhibited almost completely by the pretreatment of KC-404, which is reported to have antagonistic action against LTC4/D4. These results suggest that allergen-induced late broncho-constrictions accompanied by airway hyperresponsiveness in guinea pigs are associated with the extensive infiltration into the airway lumen of inflammatory cells, and are concerned with the release of LTs. We also suggest that this LBR guinea pig model is useful in studying the mechanisms of the occurrence of LAR in humans, and in evaluating the action of anti-allergic drugs in LAR.

[Fibrogenesis and glycoconjugates]

Glycosamnoglycan (GAG)s and fibronectin (FN) in the bronchoalveolar lavage fluid (BALF) from cases of sarcoidosis and interstitial pneumonitis, FN in the lung of paraquat-induced fibrosis in humans, and FN in the experimental bleomycin-lung of rats were quantified and partially characterized. It was found that the BALF from cases of sarcoidosis and interstitial pneumonitis, whose chest X-ray film showed persistent abnormalities despite treatment, contained detectable amounts of GAG's. There was a statistically significant difference in the FN content of BALF between patients with higher and those with lower uptake of Ga into the lung field. FN in BALF mainly consisted of a 440 Kd molecular species which is identical to that of plasma FN. In experimental bleomycin-lung of rats, FN increased prior to fibrogenesis of the lung. In paraquat lung an increase of GAG's paralleled an increase of collagen. Electron microscopy revealed that dermatan sulfate was closely associated with collagen fibers in the human lung. These data suggested a close relationship between glyconjugates and fibrogenesis.

[Experimental studies on the pathogenesis and development of interstitial pneumonia and pulmonary fibrosis]

In order to elucidate the mechanism of pulmonary fibrosis development, analysis of bronchoalveolar lavage fluid (BALF), alveolar macrophage function and histological examination were performed in bleomycin (BLM) treated mice and MRL/lpr mice. In the BLM-treated group, swelling of type II alveolar cells, increase of phospholipids and total cell counts in BALF were observed at the early stage following BLM administration. Lysosomal enzyme activities, total protein volume, superoxide production and IL-1 production of alveolar macrophages peaked at the second week after completing BLM administration. In MRL/lpr mice, lymphocytes infiltration in the interstitium, perivascular and peribronchial granuloma formation were observed at 24 weeks old. Analysis of BALF revealed the increase of total cell counts, lymphocyte counts, and fibronectin volume. No significant difference was observed in total protein and phospholipid volume between MRL/lpr mice and MRL/n mice (control mice).

[Measurement of carcinoembryonic antigen, squamous cell carcinoma related antigen and neuron-specific enolase in the bronchoalveolar lavage fluid in patients with peripheral lung cancer]

Carcinoembryonic antigen (CEA), squamous cell carcinoma related antigen (SCC) and neuron-specific enolase (NSE) in bronchoalveolar lavage fluid were measured in 30 patients with peripheral lung cancer, 11 patients with benign lung disease and 19 healthy controls. The mean levels and positive rates of lavaged fluid CEA were 128.0 +/- 16.9 ng/mg and 33.3% in patients with lung cancer, 68.1 +/- 25.9 ng/mg and 9.1% in patients with benign lung disease, and 68.3 +/- 11.6 ng/mg and 5.2% in healthy controls, respectively. The mean levels and positive rates of lavaged fluid CEA in patients with lung cancer were significantly higher than those in patients with benign lung disease (p less than 0.05) and those in healthy controls (p less than 0.05). The mean levels of lavaged fluid SCC and NSE showed no significant difference between cases of lung cancer and benign lung disease or healthy controls. No lavaged tumor marker level in patients with lung cancer showed any close correlation with histologic types and serum levels. In conclusion, measurement of lavaged fluid CEA was considered to be useful in the differential diagnosis of peripheral lung cancer.