Toluene diisocyanate-stimulated release of arachidonic acid metabolites in the organ bath from guinea-pig airways

This study was designed to evaluate whether metabolites of arachidonic acid play a role in the contractile response to toluene diisocyanate in isolated guinea pig airways. In control experiments we collected the supernatant from an organ bath over a time period of 2 h, after the addition of toluene diisocyanate (100 and 300 microM), and after the addition of toluene diisocyanate (300 microM) in the presence of indomethacin (5 microM). We measured prostaglandin E2, 6-keto-prostaglandin F1 alpha, prostaglandin F2 alpha, thromboxane B2, leukotriene B4, leukotriene C4/D4/E4/F4 by radioimmunoassays. Levels of prostaglandin F2 alpha and 6-keto-prostaglandin F1 alpha increased significantly after addition of toluene diisocyanate in the absence of indomethacin. These results suggest that prostaglandins are involved in toluene diisocyanate-induced contractions in guinea-pig airways.

Comparison of fluticasone propionate with beclomethasone dipropionate in moderate to severe asthma treated for one year. International Study Group

BACKGROUND

High dose inhaled glucocorticosteroids are increasingly used in the management of patients with moderate to severe asthma. Although effective, they may cause systemic side effects. Fluticasone propionate is a topically active inhaled glucocorticosteroid which has few systemic effects at high doses.

METHODS

Fluticasone propionate, 1.5 mg per day, was compared with beclomethasone dipropionate at the same dose for one year in patients with symptomatic moderate to severe asthma; 142 patients received fluticasone propionate and 132 received beclomethasone dipropionate. The study was multicentre, double blind and of a parallel design. For the first three months patients attended the clinic every four weeks and completed daily diary cards. For the next nine months they were only seen at three monthly intervals in the clinic.

RESULTS

During the first three months diary card peak expiratory flow (PEF) rate and lung function measurements in the clinic showed significantly greater improvement in patients receiving fluticasone propionate (difference in morning PEF 15 l/min (95% CI 6 to 25)), and these differences were apparent at the end of the first week. The improved lung function was maintained throughout the 12 month period and the number of severe exacerbations in patients receiving fluticasone propionate was reduced by 8% compared with those receiving beclomethasone dipropionate. No significant differences between the two groups were observed in morning plasma cortisol levels, urinary free cortisol levels, or response to synthetic ACTH stimulation. In addition, both the rates of withdrawal and of adverse events were low, and there were fewer exacerbations of asthma with fluticasone propionate than beclomethasone dipropionate.

CONCLUSIONS

This study shows that fluticasone propionate in a daily dose of 1.5 mg results in a significantly greater increase in PEF and asthma control than the same dose of beclomethasone dipropionate, with no increase in systemic or other side effects.

The effect of compound 48/80 on contractions induced by toluene diisocyanate in isolated guinea-pig bronchus

We have investigated the ability of compound 48/80 and of histamine H1 and H2 receptor antagonists to inhibit toluene diisocyanate-induced contractions in isolated guinea-pig bronchi. Compound 48/80 (100 micrograms/ml) significantly inhibited toluene diisocyanate-induced contractions. By contrast, the two histamine H1 and H2 receptor antagonists, chlorpheniramine (10 microM) and cimetidine, (10 microM) did not affect toluene diisocyanate-induced contractions, but significantly inhibited contractions induced by exogenously applied histamine (100 microM) and by 48/80. We investigated which mechanisms 48/80 used to inhibit toluene diisocyanate-induced contractions, paying particular attention to the possible involvement of capsaicin-sensitive primary afferents. In vitro capsaicin desensitization (10 microM for 30 min followed by washing) significantly reduced compound 48/80-induced contractions. A capsaicin-resistant component of contraction was also evident. Ruthenium red (3 microM), an inorganic dye which acts as a selective functional antagonist of capsaicin, did not affect 48/80-induced contraction. MEN 10,207 (Tyr5,D-Trp6,8,9,Arg10)-neurokinin A (4-10) (3 microM) a selective antagonist of NK2-tachykinin receptors significantly reduced 48/80-induced contractions. These results show that compound 48/80 inhibits toluene diisocyanate-induced contractions in isolated guinea-pig bronchi. It is likely that two mechanisms are involved in the inhibition: (1) the release of mediators other than histamine by mast cells, (2) an effect of 48/80 on sensory nerves.

Activated T-lymphocytes and macrophages in bronchial mucosa of subjects with chronic bronchitis

To examine the nature and the degree of leukocyte infiltration and to determine the state of activation of cells in bronchial mucosa of subjects with chronic bronchitis, bronchoscopy was performed in 10 subjects with a history of cigarette smoking and chronic sputum production and in six normal nonsmoking control subjects. Lobar bronchial biopsies were examined using histochemical and immunohistochemical techniques. Subjects with chronic bronchitis had an increased number of total leukocytes (CD45 positive cells), both in the epithelium and in the lamina propria, than did the control subjects (p < 0.05), whereas the numbers of neutrophils, eosinophils, and mast cells were similar in the two groups. There was a significant increase in the numbers of macrophages (p < 0.01) and of T-lymphocytes (CD3 positive cells) (p < 0.05) in the lamina propria of chronic bronchitics, whereas the relative proportions of CD4 and CD8 positive cells were similar in the bronchitics and the control subjects. Subjects with chronic bronchitis also had an increased expression of markers of lymphocyte activation, i.e., an increased number of interleukin-2 receptor positive cells (CD25 positive cells) (p < 0.05) and an increased number of very late activation antigen (VLA-1) positive cells (p < 0.05). In conclusion, the present study provides evidence for mononuclear cell infiltration and for T-cell activation in bronchial mucosa of subjects with chronic bronchitis, supporting the involvement of these cells in the pathogenesis of the disease.

Effect of bumetanide on toluene diisocyanate induced contractions in guinea pig airways

BACKGROUND

The loop diuretic frusemide has been shown to inhibit the bronchoconstrictor response to exercise, inhaled allergen, distilled water, adenosine, and sodium metabisulphite. Toluene diisocyanate contracts smooth muscle by activating capsaicin sensitive nerves and causes asthma that shares many features with allergen induced asthma.

METHODS

The study was designed to assess the effect of two loop diuretics, bumetanide (10 and 100 microM) and frusemide (100 microM), on smooth muscle contraction induced by toluene diisocyanate (0.03-1000 microM) in guinea pig airways with and, in the case of bumetanide, without epithelium. The effect of bumetanide on the response to acetylcholine, neurokinin A, and electrical field stimulation in guinea pig bronchial smooth muscle rings was also examined.

RESULTS

Bumetanide (10 and 100 microM) had no effect on toluene diisocyanate induced contraction whether airway epithelium was present or not. Frusemide (100 microM) caused no significant inhibition of toluene diisocyanate induced contraction (mean reduction on the entire curve 25%). Bumetanide inhibited non-adrenergic, non-cholinergic contraction induced by electrical field stimulation of bronchi pretreated with atropine (1 microM) and indomethacin (5 microM) and this inhibition was inversely related to the frequency of stimulation, suggesting that bumetanide may be inhibiting transmitter release at the prejunctional level. Bumetanide and frusemide did not inhibit the responses to exogenous acetylcholine (0.1 microM) or neurokinin A (1 nM).

CONCLUSIONS

Bumetanide and frusemide in doses that are known to inhibit non-adrenergic, non-cholinergic contraction due to electrical field stimulation failed to inhibit the response to toluene diisocyanate in guinea pig airways.

Protection of erdosteine on smoke-induced peripheral neutrophil dysfunction both in healthy and in bronchitic smokers

The purpose of the present study was to determine whether erdosteine and its metabolites (substances containing thiol groups) can prevent the alteration of the chemotactic function of polymorphonuclear cells (PMN) from peripheral blood induced by cigarette smoke of eight healthy non-smoking volunteers, when incubated in vitro before smoke exposure, and whether oral treatment with erdosteine (900 mg/day) for two weeks might restore the chemotaxis of PMN, either from eight healthy or from 16 chronic bronchitic smokers. The chemotactic stimuli in vitro were casein, lipopolysaccharides (LPS), and formyl-methionyl-leucyl-phenyalanine (FMLP). The results of the study in vitro have confirmed that PMN from non-smoking volunteers shows a reduced chemotactic responsiveness when exposed in vitro to smoke. This can be partially prevented in a dose-related manner by pre-incubation with erdosteine, its metabolites, cysteine, and glutathione (metabolites I and II being at least 10 times more active than the intact substance and the known biological standards also containing thiol groups). The experiment on PMN from healthy smokers (in a double-blind crossover design versus placebo) has indicated that the chemotaxis can be improved only after treatment with erdosteine. The same observation has been made in the experiment on PMN from smokers affected by chronic bronchitis (in a double-blind design versus placebo with two distinct groups). In these patients the phagocytic and bactericidal activities of PMN were not affected by the smoke and therefore, neither one was influenced by erdosteine treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

The products of the reaction between toluene diisocyanate and water contract isolated guinea pig bronchi

We have investigated the ability of the products of the reaction between toluene diisocyanate (TDI) and water to contract bronchial smooth muscle. The experiments were performed in isolated guinea pig bronchi. TDI, both 2,4- and 2,6-toluenediamine (TDA) and mixtures of 2,4- and 2,6-TDA (ratio 80:20 and 20:80) caused concentration-dependent contraction in the isolated bronchi. The mixture of disubstituted urea and biuret also contracted the bronchi, but not in a concentration-dependent fashion. Our results provide evidence that all products of the reaction between toluene diisocyanate and water have the ability to contract isolated bronchial smooth muscle in guinea pigs. Whatever the role of toluenediamine in the adverse respiratory effects induced by exposure to isocyanates, our findings reveal the necessity of in vivo studies on the metabolism of inhaled toluene diisocyanate in humans to improve our understanding of the mechanism of action of isocyanates.

Theophylline inhibits late asthmatic reactions induced by toluene diisocyanate in sensitised subjects

Toluene diisocyanate (TDI)-induced asthma is a frequent occupational airway disease. To determine whether a calibrated dosage of oral slow-release theophylline inhibits asthmatic reactions and the associated increase of airway responsiveness to methacholine induced by TDI, we examined six asthmatic subjects who developed a late or a dual asthmatic reaction after TDI inhalation challenge. We administered oral slow-release theophylline or placebo to each subject for 7 days according to a double-blind, randomized, cross-over study design. When the subjects received a placebo, TDI caused a late or a dual asthmatic reaction. When the subjects received theophylline. TDI caused significantly reduced late asthmatic reactions. Mean serum theophylline concentrations were within the therapeutic range. Theophylline neither modified the baseline airway responsiveness to methacholine, nor the increase of airway responsiveness to methacholine induced by TDI. These results suggest that slow-release theophylline may improve TDI-induced late asthmatic reactions, but it does not change the baseline airway responsiveness to methacholine and the increase of airway responsiveness to methacholine induced by TDI.

The effect of phosphoramidon and epithelium removal on toluene diisocyanate-induced contractions in guinea-pig bronchi

To evaluate the role of airway neutral endopeptidase 24.11 (NEP) and epithelium removal in the contraction of airway smooth muscle in response to toluene diisocyanate (TDI), we studied the effects of the NEP inhibitor, phosphoramidon, on TDI-induced contractions of guinea-pig bronchial rings with intact epithelium and without epithelium. In preparations with intact epithelium, phosphoramidon (10 microM) potentiated the contractile response to TDI (0.3 mM) (mean +/- SEM, 23.7 +/- 2.5% versus 67.9 +/- 10.3%, p less than 0.01). Phosphoramidon also increased TDI-induced contractions in tissues without epithelium (36.9 +/- 4.9% versus 52.5 +/- 7.1%, p less than 0.05). Removal of the epithelium increased the contractile response to TDI (23.7 +/- 2.5% versus 36.9 +/- 4.9%, p less than 0.05). These results demonstrate the response to TDI is increased in epithelium-free compared to intact bronchi and that NEP 24.11 modulates the effects of endogenously released tachykinins by TDI at all of the sites where NEP is found in the airways.

The effect of phosphoramidon and epithelium removal on toluene diisocyanate-induced contractions in guinea-pig bronchi

To evaluate the role of airway neutral endopeptidase 24.11 (NEP) and epithelium removal in the contraction of airway smooth muscle in response to toluene diisocyanate (TDI), we studied the effects of the NEP inhibitor, phosphoramidon, on TDI-induced contractions of guinea-pig bronchial rings with intact epithelium and without epithelium. In preparations with intact epithelium, phosphoramidon (10 microM) potentiated the contractile response to TDI (0.3 mM) (mean +/- SEM, 23.7 +/- 2.5% versus 67.9 +/- 10.3%, p less than 0.01). Phosphoramidon also increased TDI-induced contractions in tissues without epithelium (36.9 +/- 4.9% versus 52.5 +/- 7.1%, p less than 0.05). Removal of the epithelium increased the contractile response to TDI (23.7 +/- 2.5% versus 36.9 +/- 4.9%, p less than 0.05). These results demonstrate the response to TDI is increased in epithelium-free compared to intact bronchi and that NEP 24.11 modulates the effects of endogenously released tachykinins by TDI at all of the sites where NEP is found in the airways.

Role of bromhexine in exacerbations of bronchiectasis. Double-blind randomized multicenter study versus placebo

The effectiveness of bromhexine in the treatment of patients with bronchiectasis, in a stage of clinical exacerbation, was assessed in a double-blind, placebo-controlled trial involving 88 in-patients. Bronchiectasis was diagnosed by bronchography and/or CT scan. Bromhexine or matched placebo was administered as 30-mg capsules three times daily per os. Ceftazidine, 1 g i.m., was given to all patients once a day for the first week only. Bromhexine seemed to improve the clinical picture, with significantly positive trends for expectoration, quantity of sputum and auscultatory findings. It also increased the FEV1 and was well-tolerated. Both patients and investigators judged it efficacious.

The effect of retinoic acid on thymidine incorporation and morphology of corneal stromal fibroblasts

The effect of retinoic acid on DNA synthesis and cell morphology was studied using corneal stromal fibroblasts in culture. All-trans retinoic acid induces an increase in DNA synthesis after 24 hours of exposure. Autoradiographic studies of 3H-thymidine incorporation into corneal stromal cells exposed to 10(-6) M retinoic acid for 24 hours showed an increase in labeling which ranged from 19.2% to 67.6% over control cultures. Scintillation analysis of labeled cultures also showed an increase in incorporation of 3H-thymidine into cells treated with 10(-6) M retinoic acid, with increases ranging from 21.8% to 114.7% above control cultures. Exposure of cultured corneal stromal cells to 10(-6) M retinoic acid resulted in a dramatic change in cell morphology such that they changed from spindle-shaped to round, flattened cells which were epithelioid in appearance. These data demonstrate that biological activity of retinoic acid in stromal fibroblasts and imply a role for vitamin A in maintenance of stroma structure and function.

Increased bronchial responsiveness in primary and secondary Sjogren's syndrome

We examined one group of 33 patients with primary Sjogren's syndrome, one group of 17 patients with secondary Sjogren's syndrome, i.e. associated with other connective tissue diseases, and one group of 14 patients with connective tissue diseases but without Sjogren's syndrome. In each patient we obtained chest radiographs and measured lung volumes, carbon monoxide diffusing capacity and airway responsiveness to methacholine. We observed no difference in chest radiograph abnormalities, in lung volumes and in carbon monoxide diffusing capacity among the three groups. However, we found a slight but significant increase of bronchial responsiveness in patients with primary and secondary Sjogren's syndrome compared with patients with connective tissue disorders but without Sjogren's syndrome. Thus PD20FEV1 methacholine was 1.07 mg (1.2) (geometric mean and GSEM) in primary Sjogren's syndrome, 0.91 mg (1.4) in secondary Sjogren's syndrome (NS), and 2.24 mg (1.09) in patients with connective tissue diseases but without Sjogren's syndrome (t = 2.59 and t = 2.8, both p less than 0.05, vs primary and secondary Sjogren's syndrome, respectively). These results show that some patients with Sjogren's syndrome have mild bronchial hyperresponsiveness, which may be related to the specific airway abnormalities of this disease.

Increased bronchial responsiveness in primary and secondary Sjögren's syndrome

We examined one group of 33 patients with primary Sjögren's syndrome, one group of 17 patients with secondary Sjögren's syndrome, i.e. associated with other connective tissue diseases, and one group of 14 patients with connective tissue diseases but without Sjögren's syndrome. In each patient we obtained chest radiographs and measured lung volumes, carbon monoxide diffusing capacity and airway responsiveness to methacholine. We observed no difference in chest radiograph abnormalities, in lung volumes and in carbon monoxide diffusing capacity among the three groups. However, we found a slight but significant increase of bronchial responsiveness in patients with primary and secondary Sjögren's syndrome compared with patients with connective tissue disorders but without Sjögren's syndrome. Thus PD20FEV1 methacholine was 1.07 mg (1.2) (geometric mean and GSEM) in primary Sjögren's syndrome, 0.91 mg (1.4) in secondary Sjögren's syndrome (NS), and 2.24 mg (1.09) in patients with connective tissue diseases but without Sjögren's syndrome (t = 2.59 and t = 2.8, both p less than 0.05, vs primary and secondary Sjögren's syndrome, respectively). These results show that some patients with Sjögren's syndrome have mild bronchial hyperresponsiveness, which may be related to the specific airway abnormalities of this disease.

[Cefotetan in the therapy of respiratory infections. Multicenter research]

In a controlled multicenter trial 291 patients have been treated with cefotetan. They suffered from acute or chronic exacerbated bronchopulmonary disorders. In 110 patients it was possible to identify the etiological agent: enterobacteria (62), non-fermentative gram-negative bacilli (10), Haemophilus influenzae (8), Branhamella catarrhalis (1), Streptococcus pneumoniae (19), Staphylococcus aureus (12), Streptococcus pyogenes (4). In the exacerbations of chronic bronchitis (203), cefotetan was generally administered at the dose of 1 g/12 h i.m., whereas it was administered at the dose of 2 g/12 h i.v. in acute infection. The mean duration of therapy was 8.8 days. Positive clinical results were obtained in 251 patients (86.2%) with eradication of the pathogen initially isolated in 90.5% of cases. Cefotetan showed good local and general tolerance. The results obtained confirm those of studies concerning limited numbers of patients and show the efficacy of cefotetan both in acute and chronic pathologies, also in patients with serious involvement of their general conditions (concomitant pathologies, high mean age).

[Trends in tuberculosis in the Ferrara region 1984-1987]

The Authors investigate some epidemiologic aspects of the patients affected by Tuberculosis in Ferrara's area, during 1984-1987. The patients with Tuberculosis and submitted to this study were singled out using documents from: Chair and Department of Respiratory Diseases, University of Ferrara School of Medicine, Tresigallo Hospital; Pneumology and Occupational Medicine Service, USL 31, Ferrara; TBC Assistance Bureau, INPS, Ferrara. A total of 563 "cases" of Tuberculosis were recognized; of them, 138 had a relapse of a previous disease, 27 had multiple and contemporary diseases, and 18 had different types of Tuberculosis in various periods of the study. The analysis of the data shows that Tuberculosis is still present in our area, in some cases with clinical features of aggressiveness. In relation to sex and age, a significant increase of Tuberculosis in females during 1986-87, and a significant amount of young patients, were observed. Moreover, a significant rise of extrapulmonary forms, particularly in females, was stressed as well as the onset of primary Tuberculosis during 1987. The very important problem of bacillar spread, and its implication with a report of Tuberculosis in food-stuff sellers and health-staff, are finally discussed. The Authors' conclusion's the following: a more active epidemiologic surveillance of Tuberculosis is still required.

Neonatal metabolic acidosis: effect of chloride from normal saline flushes

Metabolic Acidosis is a reported complication of total parenteral nutrition (TPN). A large number of infants receiving TPN in an NICU were noted to have metabolic acidosis. We evaluated the effect of lowering the chloride intake on the incidence of metabolic acidosis in low birth weight (LBW) infants on TPN. Standard TPN solutions were adjusted to provide about 2-3 mEq/kg/day chloride instead of 5-7 mEq/kg/day provided previously. Most infants on TPN received approximately another 1-3 mEq/kg/day from intravenous and arterial line flushes with normal saline. Ten infants who had been on the original TPN solutions were compared to 10 infants who were on the revised TPN solutions. Serum pH, bicarbonate, and base deficit were used to measure acidosis. Medical records were reviewed for the number of days the infants had abnormal values. Serum chloride levels were also recorded. While similar in gestational age, birth weight, age during study period, days on TPN, and days on orally supplemented parenteral nutrition, the group with higher chloride intake had significantly more days of metabolic acidosis. They also had significantly higher serum chlorides. It is concluded that a total chloride load in excess of 6 mEq/kg/day in LBW infants receiving TPN is associated with more metabolic acidosis. Also, if saline is used for clearing of intravenous and arterial lines, standard TPN solutions should be formulated with consideration of the total chloride load.