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A 79-year-old woman presented with chronic dyspnea and hyperventilation. There was no evidence of pulmonary disease. Hyperventilation persisted during sleep and after high-dose administration of a narcotic. A head MRI revealed bilateral medial thalamic infarctions. Central neurogenic hyperventilation was diagnosed in this alert patient. The case may illustrate a role for the thalamus in regulating ventilation, but another small infarct not visible on MRI also could be responsible.

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STUDY OBJECTIVES: To determine if African-American and white patients with asthma (1) differ in the words they use to describe their breathlessness, and (2) differ in their perception of breathlessness. DESIGN: Descriptive cross-sectional design. SETTING AND PARTICIPANTS: The study setting was located in Northern California, an ethnically and economically diverse area. A total of 32 subjects, 16 per group, completed the study. MEASUREMENTS: All had a provocation concentration of methacholine chloride causing a 30% fall in FEV(1) (PC(30)) of

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BACKGROUND: Bronchiolitis obliterans occurs in 30% to 80% of lung-transplant recipients and is a direct cause of death in more than 40% of patients with this complication. This study assessed the potential utility of measuring fibroblast-proliferative activity in bronchoalveolar lavage fluid from lung-transplant recipients to better understand the pathogenesis of this process. METHODS: The capacity of bronchoalveolar lavage fluid obtained from transplant recipients, during routine surveillance bronchoscopy, to stimulate the proliferation of human lung fibroblasts in vitro was assessed retrospectively and compared to that of control subjects. For each recipient, a correlation was made between the fibroblast-proliferative activity in serial lavage samples over time and the other modalities employed for detecting post-transplant complications including spirometry, transbronchial lung biopsy, and high-resolution computed tomography. RESULTS: There was a significant difference in fibroblast-proliferative activity between volunteer and transplant recipient groups (p = 0.002). Further, for each transplant recipient, the decline in the forced expired flow rate between 25% and 75% of expired volume (FEF(25%-75%)) was correlated with the mean fibroblast-proliferative activity during the period of this study (r = 0.83; p = 0.04). CONCLUSIONS: A sustained increase in fibroblast-proliferative activity in lavage supernatant precedes both histologic and physiologic evidence of bronchiolitis obliterans. Relative to an increase in fibroblast-proliferative activity or abnormalities in FEF25%-75%, a decrease in forced expiratory volume in 1 second is a late finding.

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STUDY OBJECTIVE: To determine whether expandable metal stent placement for benign airway lesions improves pulmonary function. DESIGN: Case series. SETTING: University medical center. PATIENTS: Nine patients who underwent balloon-mediated expandable metal stent deployment for airway obstruction due to benign etiologies. RESULTS: All nine patients had expandable stents deployed for benign airway lesions using fiberoptic bronchoscopy and fluoroscopic guidance. Pulmonary function improved after stent placement. The mean FVC increased by 388 mL (95% confidence interval [CI], 30 to 740 mL), the mean peak expiratory flow (PEF) increased by 1,288 mL (95% CI, 730 to 1,840 mL), the mean FEV1 increased by 550 mL (95% CI, 240 to 860 mL), and the mean forced expiratory flow between 25% and 50% of vital capacity (FEF25-75%) increased by 600 mL (95% CI, 110 to 1,090 mL). Corresponding relative measurements included increases in FVC (12%), PEF (95%), FEV1 (38%), and FEF25-75% (87%). The complete characterization of a benign airway obstruction generally required a multimodal approach. CONCLUSIONS: Expandable metal stent placement appears to be an effective therapy for benign airway obstruction.

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A study of 51 patients undergoing elective major abdominal surgery was carried out to determine the incidence of postoperative respiratory failure requiring mechanical ventilation for more than 24 h and which preoperative and intraoperative factors are associated with this respiratory complication. Mechanical ventilation for more than 24 h was required in 12 of the 51 patients. These 12 patients had a significantly longer stay in the intensive care unit and in the hospital than the patients who were successfully extubated in the postoperative period. Also, there was a trend for a higher mortality in the ventilated group compared to the group of patients who did not require postoperative ventilation. Preoperative abnormalities in FEV1 did not identify which patients were destined to require postoperative ventilation. Significant differences for the ventilated versus the nonventilated patients included a longer history of cigarette smoking, a lower preoperative PaO2, and a large intraoperative blood loss.

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Oxygen (O2) has been reported to improve exercise tolerance in some patients with chronic obstructive pulmonary disease (COPD) despite only mild resting hypoxemia (PaO2 greater than 60 mm Hg). To confirm these prior studies and evaluate potential mechanisms of benefit, we measured dyspnea scores by numeric rating scale during cycle ergometry endurance testing and correlated the severity of dyspnea with right ventricular systolic pressure (RVSP) measured by Doppler echocardiography during a separate supine incremental exercise test. Both sets of exercise were performed according to a randomized double-blind crossover protocol in which patients breathed compressed air or 40% O2. We studied 12 patients with severe COPD (FEV1 0.89 +/- 0.09 L [mean +/- SEM], FEV1/FVC 37 +/- 2%, DLCO 9.8 +/- 1.5 ml/min/mm Hg[47% of predicted], PaO2 71 +/- 2.6 mm Hg). With endurance testing on compressed air, PaO2 did not change significantly in the group as whole (postexercise PaO2 63 +/- 5.1 mm Hg, p = NS), but did fall to less than 55 mm Hg in four patients from this group. Duration of exercise increased on 40% O2 from 10.3 +/- 1.6 to 14.2 +/- 1.5 min (p = 0.005), and the rise in dyspnea scores was delayed. Oxygen delayed the rise in RVSP with incremental exercise in all patients and lowered the mean RVSP at maximum exercise from 71 +/- 8 to 64 +/- 7 mm Hg (p less than 0.03). Improvement in duration of exercise correlated with decrease in dyspnea (r2 = 0.66, p = 0.001) but not with decreases in heart rate, minute ventilation, or RVSP.(ABSTRACT TRUNCATED AT 250 WORDS)

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To test our hypothesis that neutrophil elastase plays a role in airway hypersecretion associated with the allergic late-phase response, using an isolated tracheal segment system in vivo and measuring lysozyme activity in the perfusate of the lumen as a marker of submucosal gland secretion over 8 h, we studied the response of five allergic dogs to ragweed. The dogs were exposed on separate occasions to specific allergen, to allergen vehicle, and to allergen in the presence of a selective neutrophil elastase inhibitor, ICI 200,355. Allergen exposure caused a marked increase in lysozyme secretion that was significantly increased at 4, 6, and 8 h compared with controls and ICI 200,355-treated dogs. Neutrophil elastase appeared in the perfusate after allergen exposure and was positively correlated with lysozyme secretion at 8 h. These findings suggest that neutrophil elastase plays an important role as a secretagogue in the allergic late-phase response.

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Transforming growth factor-beta (TGF beta) promotes deposition of extracellular matrix and is associated with fibrotic conditions both in experimental animals and in humans. Although a role for mast cells has been suspected in the pathogenesis of fibrosis, no potent mediator capable of stimulating fibroblast growth or extracellular matrix deposition has been identified in mast cell supernatants. We report here the constitutive production of TGF beta 1 by four dog mastocytoma cell lines. TGF beta 1 was identified by characteristic biologic activity, blockade of biologic effect by specific neutralizing antibody, and by recognition of a band with the appropriate migration by western blot. TGF beta 1 mRNA, but not TGF beta 2 or TGF beta 3 mRNA, was also produced constitutively by all four cell lines. Quantitation by bioassay revealed baseline TGF beta secretion of approximately 1 ng/10(6) cells over 48 h. Stimulation of mastocytoma cells with phorbol ester increased the rate of release of TGF beta 1, most markedly in the first 30 min after stimulation, without increasing TGF beta 1 mRNA. Dog mastocytoma cells produced TGF beta 1 primarily in a latent form, inactive until treated with acid. Both pure TGF beta 1 and TGF beta-containing mastocytoma cell-conditioned media inhibited mitogenesis and proliferation in dog mastocytoma cell lines, suggesting that mast cell tumor lines would not grow preferentially based on their ability to produce TGF beta. These studies may make possible further investigation of the mechanism by which mast cells contribute to the induction of fibrosis.

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It is suspected that mast cells play a part in the pathogenesis of fibrotic diseases, but the mediators that might be involved in induction of fibrosis have not been identified. We asked whether cultured dog mast cell lines produced growth factor(s) for fibroblasts. Three mastocytoma cell lines were found to secrete proliferative activity for human, hamster, and rabbit fibroblasts. Both mastocytoma cell-conditioned medium and cell extract served as competence factors for induction of DNA synthesis in confluent mouse Swiss 3T3 fibroblasts. The mitogenic activity in the conditioned medium was stable to heat, acid, and high concentrations of chaotropic agents or organic solvents but was decreased by treatment with proteases or reducing agents. The activity had an apparent molecular mass of 10 kD and did not bind to heparin. Activity eluted in a single peak from reverse-phase HPLC, and retention time differed from that of typical mesenchymal mitogens. We offer the hypothesis that mast cells produce growth factors for fibroblasts, possibly including a novel growth factor, and that this may contribute to pathologic fibrosis.

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Pulmonary arteriovenous malformations (AVM) lead to chronic hypoxemia and systemic emboli. These lesions can now be treated by catheter embolization. In order to examine physiologic abnormalities during exercise in AVM patients, and to evaluate functional improvement after therapeutic embolization, eight patients underwent detailed physiologic studies at rest and during exercise before and after therapeutic embolization. Before treatment, six patients noted dyspnea on exertion and three had symptoms suggesting paradoxical embolism. Resting studies showed hypoxemia, abnormally increased shunt fractions, chronic alveolar hyperventilation, mild decreases in diffusing capacity, and abnormal wasted ventilation (VD). During exercise, oxygenation changed little from the resting values but VD increased markedly. Functional impairment was observed in most patients, and was correlated with shunt fraction. Obliteration of the AVM was accomplished by therapeutic embolization with placement of coils or balloons in the feeder vessels. This treatment resulted in immediate relief of dyspnea and improvement in resting PaO2 and shunt fraction. Exercise studies after embolization showed improvement in exercise capacity and gas exchange. However, chronic alveolar hyperventilation and reduced diffusing capacity remained unchanged. In summary, therapeutic embolization effectively reduces the degree of shunting, with improvement in respiratory symptoms, exercise capacity, and gas exchange at rest and during exercise. The abnormally decreased diffusing capacity and increased VD suggest the presence of a diffuse pulmonary vascular abnormality, of which further study is warranted.

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Pulmonary manifestations are not infrequent in the L-tryptophan-induced eosinophilia-myalgia syndrome (EMS). However, previous reports have not described the results of longitudinal pulmonary function, exercise testing, high-resolution computerized tomographic (HRCT) scanning of the chest, or detailed bronchoalveolar lavage (BAL) analysis. We report six patients with EMS who had dyspnea. The diffusing capacity for carbon monoxide was decreased in five patients tested. Exercise testing with arterial blood gas sampling in three patients was consistent with pulmonary vascular or parenchymal disease. Serial exercise testing in two of these patients demonstrated marked improvement temporally associated with corticosteroid treatment. In four patients, HRCT scanning of the chest was abnormal. One of these patients showed no abnormality on routine chest roentgenogram. Two patients undergoing BAL exhibited increased eosinophils in the lavage fluid; a third had elevated lymphocytes. Serial measurements of fibroblast proliferation-stimulating-activity in samples of BAL fluid obtained from serial examinations in two patients exhibited heightened pretreatment activity that returned to the normal range following corticosteroid therapy. In these two patients, increased proportions of T-suppressor/cytolytic (CD8+) cells were observed in the BAL fluid. Despite aggressive immunosuppressive therapy, one of the patients died of respiratory failure. Another remains markedly dyspneic with pulmonary hypertension. Of the remaining four patients, two exhibited resolution of pulmonary symptoms after systemic corticosteroid therapy, and two experienced partial improvement.

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It has been hypothesized that the dissolution of mast cell granules at the time of degranulation results from proteoglycan cleavage coupled to exocytosis. To address this hypothesis, we studied granule proteoglycan before and after exocytosis in dog mastocytoma cells, which solubilize granule contents during exocytosis. 35S-labeled proteoglycans were extracted from unstimulated whole cells and cell degranulation supernatant. Sequential anion-exchange and gel filtration chromatography, followed by specific glycosaminoglycan digestion, identified chondroitin sulfate and heparin glycosaminoglycan and proteoglycan in unstimulated cells and degranulated material alike. Glycosaminoglycan type and charge density in degranulation supernatant were unchanged compared with unstimulated cells. There was no decrease in proteoglycan size with cell activation and exocytosis. Thus, granule release and solubilization does not appear to require exocytosis-coupled degradation of granule proteoglycans. Release in association with high-m.w. proteoglycans may serve to limit rates of diffusion and activity of proteases and other mast cell mediators.

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Dog mastocytomas (anatomic and biochemical features comparable to normal dog and human mast cells) were used to study actions of mast cell mediators on several airway effector systems. We showed mastocytoma cell adherence to both cultured tracheal epithelial cells and tracheal tissue sections for greater than 48 h that was abolished completely by pretreatment of mast cells with proteases. This mast cell-epithelial cell adhesion-interaction reaction is probably mediated by a mast cell plasma membrane protein. Mast cell mediators stimulate short circuit current and ion flux across dog tracheal epithelia mounted in Ussing chambers. Pretreatment of epithelia with indomethacin blocks this effect, probably by inhibiting LTC4-induced activation of epithelial cyclooxygenases. Mastocytoma cells also increase secretion from cultured serous submucosal gland cells. Blockade of cyclooxygenase and lipoxygenase pathways in mastocytoma cells activated by calcium ionophore does not alter secretion of the serous cells induced by mastocytoma supernatant, but secretion induced by mastocytoma supernatant or purified mast cell chymase is markedly reduced by an inhibitor of chymase. These results suggest that mast cells can alter airway secretions not only by actions on ion flux in epithelial cells but also by actions on submucosal gland secretion; this latter action appears to be mediated by mast cell chymase. Finally, supernatants from mastocytoma cells stimulated by calcium ionophore greatly increase the sensitivity and magnitude of the contractile response of dog bronchial smooth muscle to histamine. These effects are blocked by an inhibitor of mast cell tryptase.(ABSTRACT TRUNCATED AT 250 WORDS)

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We have previously characterized dog mastocytoma cells propagated in nude mice. We have established two of these lines (C1 and C2) in continuous culture. Freshly disaggregated mastocytoma cells were cultured in Dulbecco's modified Eagle's medium (DME)-H16 mixed with 50% Ham's F12 and supplemented with histidine and 5% allergic dog serum (ADS). Cells were fed every 3 d and passaged weekly. Growth was assessed by cell count. Cell growth was best supported by culture in 5% ADS. C1 cells grow in suspension in ADS and have been passaged 55 times with a doubling time of 37.4 +/- 18.7 h (mean +/- 1 SD; n = 15). C2 cells adhere to tissue culture plastic in ADS and have been passaged 26 times with a doubling time of 49.3 +/- 12.5 h (n = 13). Morphologic and functional characteristics are unchanged from those described in cells propagated in nude mice. Histamine content for C1 is 0.46 +/- 0.18 pg/cell (n = 12) and 0.07 +/- 0.04 pg/cell (n = 6) for C2. Both lines contain the neutral protease tryptase and C2 contains chymase. Calcium ionophore A23187 or ragweed antigen caused concentration-dependent histamine release from both cell lines. C1 and C2 generate prostaglandin D2 in response to A23187. We conclude that dog mastocytoma cells can be established in continuous culture, thus providing a system for studying mast cell biology, including growth and development.

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To investigate the local intraluminal bronchial response to an antigenic stimulus, we developed a bronchoscopic double-balloon system to challenge and lavage a segment of the left main-stem bronchus. We studied whether fluid from above or below the occlusion balloons leaked into the bronchial segment. Lavage was performed before and after placement of red and blue pigments proximal and distal to the inflated balloons, respectively, and the recovered lavage fluid was analyzed visually and spectrophotometrically in three experiments. There was no evidence for pigment leakage into the segment. In six anesthetized ragweed-allergic dogs, local ragweed antigen challenges were performed. After balloon inflation in the left main-stem bronchus, we performed two baseline lavages of the interballoon segment, introduced a ragweed antigen solution, and performed two postchallenge lavages. The recovered fluid was analyzed for the concentrations of prostaglandin D2 (PGD2; radioimmunoassay) and histamine (fluorometric technique) and for total and differential cell counts. Antigen challenge was associated with a significant increase in PGD2 concentration in the recovered fluid, rising from a median of 178 pg/ml (range, 157-647) before to 919 pg/ml (range, 149-2,452) after challenge. Median histamine concentrations were 3.1 ng/ml (range, 1-5.4 ng/ml) before and 5.6 ng/ml (range, 1-16.2) after challenge (P = not significant). In four dogs, a control challenge with the antigen vehicle alone showed no change in either mediator. Changes in cell counts after challenge were inconsistent.(ABSTRACT TRUNCATED AT 250 WORDS)

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We studied the effect of a selective thromboxane-synthetase inhibitor, sodium (E)-3-[4-(1-imidazolymethyl)-phenyl]-2-propanoate) (OKY-046) on the late-phase response to antigen in ragweed-sensitized dogs. Skin biopsies were performed before and 1, 6, and 24 hours after ragweed injection. OKY-046 was infused (100 micrograms.kg-1.min) from 1 hour before until 6 hours after intracutaneous ragweed in five dogs. The early clinical response to ragweed (wheal at 20 minutes) was not changed by OKY-046. A late-phase response (induration at 6 hours) was not observed in any of the OKY-046-treated dogs but was present at 6 hours in 4/5 dogs without OKY-046. Typical mast cells responded similarly in both groups with progressive degranulation during 24 hours. Maximal degranulation of atypical mast cells was delayed to 6 hours with OKY-046, whereas these cells responded completely at 1 hour without OKY-046. The inflammatory response to ragweed followed the same pattern in both groups, but the numbers of each cell type were decreased with OKY-046. With OKY-046, the cutaneous response to histamine was not changed significantly from baseline at 6 hours but was increased (p less than 0.05) at 24 hours, whereas without OKY-046, histamine response was significantly increased at 6 hours (p less than 0.001) and 24 hours (p less than 0.01). We conclude that OKY-046 alters the antigen-induced response of atypical mast cells, the subsequent cellular and clinical late-phase response, and prevents the increase in histamine response.

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Mast cells are believed to play an important role in the pathogenesis of asthma, and several investigators have suggested that increased numbers of mast cells in the airway lumen or increased releasability of histamine from these mast cells are responsible for chronic airway hyperreactivity. To determine whether mast cells in the lumen of the airways of hyperreactive Basenji greyhound (BG) dogs differ from those of mongrel dogs with normal airway reactivity, we investigated the morphologic and functional characteristics of mast cells recovered by bronchoalveolar lavage (BAL). BAL was performed in five BG and five mongrel dogs with 900 cc of a buffered salt solution. The recovered lavage fluid contained 115 +/- 19 X 10(6) and 116 +/- 14 X 10(6) (mean +/- SEM) cells in BG and mongrel dogs, respectively. The proportion of all mast cells within the recovered cell population as enumerated after fixation with basic lead acetate and staining with alcian blue was not different in BG and mongrel dogs and averaged 0.80 +/- 0.07% and 1.1 +/- 0.3%, respectively. Typical mast cells as identified after fixation with paraformaldehyde were rare; however, significantly more mast cells were found in mongrel (0.03 +/- 0.009%) than in BG dogs (0.004 +/- 0.002%; p less than 0.02). Mast cells recovered from BG and mongrel dogs were not different in their low spontaneous histamine release (2.0 +/- 0.5% and 2.9 +/- 0.8%), their histamine release on stimulation with the calcium ionophore A23187 (maximum release 44.8 +/- 5.7% and 41.5 +/- 3.9%), and their lack of response to compound 48/80 (maximum release 5.8 +/- 1.8% and 6.1 +/- 6.0%).(ABSTRACT TRUNCATED AT 250 WORDS)

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Supernatants obtained by degranulation of dog mastocytoma cells greatly increased the sensitivity and the magnitude of the contractile response of isolated dog bronchial smooth muscle to histamine. The enhanced contractile response was reversed completely by H1-receptor antagonists and was prevented by an inhibitor of tryptase (a major protease released with histamine from secretory granules of mast cells). The potentiation of histamine-induced contractions was reproduced by active tryptase in pure form. The contractions due to the combination of histamine and purified tryptase were abolished by the Ca2+ channel blockers nifedipine and verapamil. The bronchoconstricting effects of KCl and serotonin, which, like histamine, contract airway smooth muscle by a mechanism predominantly involving membrane potential-dependent Ca2+ transport, were also potentiated by tryptase. However, the contractile effects of acetylcholine, which contracts dog airway smooth muscle by a mechanism independent of Ca2+ channels, were unaffected by tryptase. These findings show a striking promotion of agonist-induced bronchial smooth muscle contraction by mast cell tryptase, via direct or indirect effects on Ca2+ channels, and the findings therefore suggest a novel potential mechanism of hyperresponsiveness in dog bronchi.

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The cell-associated proteoglycans synthesized by three dog mastocytoma cell lines were isolated and their structural features compared. The lines were propagated as subcutaneous tumors in athymic mice for over 25 generations. In primary cell culture, all three lines incorporated [35S]sulfate into high molecular weight proteoglycans which were heterogeneous in size and glycosaminoglycan content. Two lines, BR and G, synthesized both a heparin proteoglycan (HPG) and a chondroitin sulfate proteoglycan (ChSPG) in different proportions. The third line, C2, synthesized predominantly a ChSPG with little or no detectable heparin. Gel filtration of the 35S-labeled HPG and ChSPG from the BR line on Sepharose CL-4B in dissociative conditions (4 M guanidine, Triton X-100) yielded a major polydisperse peak (Kav = 0.22) accounting for 70% of 35S activity. Under aggregating conditions (0.1 M sodium acetate) on Sepharose CL-4B, the BR proteoglycans eluted in the excluded volume. Proteoglycans from lines G and C2 also eluted in the void volume under nondissociative conditions, however the C2 line yielded additional fractions of smaller hydrodynamic size (Kav = 0.81) suggesting the presence of intracellular proteoglycan cleavage products or incompletely processed proteoglycans. As assessed by dissociative chromatography on Sepharose CL-4B, proteoglycans from the BR line were resistant to proteinase cleavage under conditions which degraded a rat chondrosarcoma proteoglycan. For all lines, glycosaminoglycans released by pronase/alkaline-borohydride had molecular weights ranging from 20,000 to 50,000 on gel filtration. For line BR, 75% of 35S-labeled glycosaminoglycans were degraded to oligosaccharides by nitrous acid, and the remaining 25% were degraded by chondroitinase ABC. Corresponding percentages for line G were 89% and 11%, and for line C2, 2% and 98%. Paper chromatography of the chondroitinase digestion products from lines BR and C2 showed products corresponding to unsaturated standards delta Di-diSB and delta Di-diSE, derived from the disaccharides IdoUA-2-SO4----GalNAc-4-SO4 and GlcUA----GalNAc-4,6-diSO4 respectively, in addition to smaller amounts of monosulfated disaccharides. Glycans from lines C2 and BR contained small quantities of a trisulfated disaccharide which was degraded to delta Di-diSB upon incubation with chondro-6-sulfatase. The results demonstrate the simultaneous presence of heparin and polysulfated chondroitin sulfate in dog mast cells of clonal origin.

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