Degree of control of physician-diagnosed asthma and COPD in Italy.

BACKGROUND: It is important for the Italian National Health Service to obtain data on the degree of control of asthma and chronic obstructive pulmonary disease (COPD) in the general population in Italy in order for balanced planning of future investments in these diseases to be made. Currently, precise estimates of these parameters are not available in literature. OBJECTIVES: In collaboration with the Italian Academy of General Practitioners (SIMG; www.simg.it) we have investigated the degree of control of physician-diagnosed asthma and COPD in Italy. METHODS: A standardised questionnaire on asthma and COPD has been self-administered to a sample of 1937 Italian family physicians (representing around 5% of all the Italian doctors involved in general practice) chosen to cover all the Italian counties. RESULTS: We have collected questionnaire data from 19,917 patients with asthma and COPD followed in their practice and 12,438 (62.4%) were correctly filled in enabling evaluation. We selected the number of emergency room visits, hospitalisations and intensive care unit admissions for asthma and COPD in the last 12 months as objective measures of the degree of asthma and COPD morbidity in these patients. The figures were respectively 12.4% (emergency room visits), 17.3% (hospitalisations) and 1.2% (intensive care unit admissions) of all patients with physician-diagnosed asthma and COPD. CONCLUSIONS: This data suggests that in Italy the morbidity of asthma and COPD remains high; representing a significant burden for the Italian National Health Service. There is a clear necessity for further studies to investigate the causes of this incomplete control.

Ectopic thymoma simulating a pericardial cyst.

We present a case of a 53 year old man with a thymoma near the pericardium, a rare ectopic localisation of thymoma. A round radiodensity found at the right cardiophrenic angle was initially suspected at the echocardiography to be a pericardial cyst. The diagnosis of thymoma was made only after histopathological examination of the surgically re-sected lesion.

Underuse of spirometry by general practitioners for the diagnosis of COPD in Italy.

BACKGROUND: The Global Initiative for Chronic Obstructive Lung Disease (GOLD) underlines that spirometry is the gold standard as the most reproducible, standardised, and objective way of measuring airflow limitation in the diagnosis and assessment of Chronic Obstructive Pulmonary Disease (COPD). However, studies undertaken in different countries have suggested a widespread underuse of spirometry by general practitioners to establish the diagnosis of COPD. Precise estimates of the prevalence of physician-diagnosed COPD in Italy are not currently available. In collaboration with the Italian Academy of General practitioners (SIMG) we have investigated the degree of use of spirometry to establish the diagnosis of COPD in Italy. METHODS: A standardised questionnaire has been self-administered to a sample of 2425 Italian general practitioners (representing 5% of all the Italian doctors involved in general practice). They have been chosen to cover each of the Italian counties. RESULTS: The prevalence of physician-diagnosed COPD was found to be approximately 4%. However, 30% of general practitioners do not use spirometry to establish the diagnosis of COPD. The main reasons given for the failure to use spirometry are (i) that spirometry is not necessary for the diagnosis of COPD or (ii) there are logistical limitations to the access of the patients to lung function laboratories. CONCLUSIONS: This data suggests that contrary to GOLD Guidelines, in Italy, as with other countries, spirometry is not always used in the diagnosis of COPD. There is a clear necessity for further education initiatives targeted to this group of physicians.

Asthma is not a common cause of severe chronic respiratory failure in non-smokers: ALOT study.

BACKGROUND: Little is known about the long-term natural history of asthma and the long-term clinical and functional consequences in non-smoking patients. From a functional point of view, non-smoking asthmatic patients may have a significantly greater decline in forced expiratory volume in one second (FEV1) compared with non-asthmatic subjects and may develop chronic irreversible (fixed) airflow limitation. This has been related to the physiological consequences of chronic airway inflammation causing airway remodeling. However these lesions are all potentially reversible and there is little radiological evidence indicating lung destruction (pulmonary emphysema), which is potentially irreversible, in non-smoking asthmatics. Severe chronic respiratory failure is the major cause of mortality in patients with severe chronic lung diseases. Domiciliary long-term oxygen therapy (LTOT) is an accepted treatment for patients with severe chronic respiratory failure. Our reasoning, therefore, was that if asthma is a cause of severe chronic respiratory failure in non-smokers we should be able to find non-smoking asthmatics within a large population of patients on LTOT. The aim of our study (Asthma and Long-term Oxygen Therapy, "ALOT") was to investigate the prevalence of non-smoking asthmatics in patients on LTOT in a multi-centre, cross-sectional study. METHODS: Between June and September 2003 we screened all subjects on long-term domiciliary oxygen therapy in three different hospitals in the North-East area of Italy (within the provinces of Ferrara and Bologna). Taken collectively, we have found one-hundred and eighty-four patients on LTOT. We have reviewed their clinical data (age, sex, smoking, history and physical examination, arterial blood gas analysis, pulmonary function). RESULTS: 114 patients (all smokers) fulfilled the diagnostic criteria for COPD. Seventy patients (all smokers) had other diseases. We were unable to find any non-smokers in our screened population of subjects on long-term domiciliary oxygen therapy. Furthermore, there was no past history of asthma and/or acute wheezing episodes in either of the patient groups. CONCLUSIONS: This data suggests that asthma is an uncommon cause of severe chronic respiratory failure necessitating long-term domiciliary oxygen therapy in non-smokers and supports the current consensus that asthma and COPD are different diseases with differing stages of severity and the concept that long-term avoidance of active smoking is fundamental for the prevention of severe chronic respiratory failure.

17beta-estradiol, but not raloxifene, decreases thrombomodulin in the antithrombotic protein C pathway.

Raloxifene is a nonsteroidal selective estrogen receptor modulator (SERM) that mimics the effects of estrogen on some plasma lipids and may have direct effects on the vascular wall. The objective of this study was to determine the effects of 17beta-estradiol, raloxifene, and LY139,478 (a related benzothiophene SERM) on the anticoagulant protein C pathway. In human vascular endothelial cells activated with interleukin-1 (IL-1), we demonstrated decreased thrombomodulin-dependent protein C activation. 17beta-estradiol reduced the anticoagulant properties of both unstimulated and IL-1-activated endothelial cells by decreasing thrombomodulin expression. In contrast, raloxifene and LY139,478 enhanced the anticoagulant properties of both unstimulated and IL-1-activated endothelial cells through upregulation of thrombomodulin. Regulation of the protein C pathway via thrombomodulin on vascular endothelium may be a novel mechanism by which SERMs could potentially confer cardioprotective effects and reduce the thrombotic risk associated with HRT in compromised patients.

Oxygen radical scavengers inhibit clastogenic activity induced by sonication of human serum.

Clastogenic factors (CF) are diffusible molecules that damage DNA. They are generated within biological media by a variety of physical and chemical stimuli. Their nature and mechanism of action remain largely unknown. Clastogenic activity can be experimentally generated by pulsed ultrasound treatment of human serum. To investigate whether oxygen radicals are involved in the clastogenic activity induced by sonication of human serum, we examined the effects on such clastogenic activity of different oxygen radical scavengers added to human serum before and after sonication. Human serum was sonicated for 50 min at 24 microW/cm2 by pulsed ultrasound. The clastogenic activity of sonicated human serum was examined in the presence or absence of oxygen radical scavengers by measuring the amount of DNA damage induced in autologous human lymphocytes, assessed with the fluorometric analysis of DNA unwinding (FADU). Sonication of human serum generated significant DNA damage in autologous lymphocytes (DNA unwinding averaged 31.79% +/- 2.1 after sonication vs. 12.82% +/- 2.6 in the controls, p < 0.005). Superoxide dismutase (SOD; 500 I.U./ml), catalase (500 I.U./ml), mannitol (50 mM), and glutathione (50 mM) completely prevented DNA damage when added before serum sonication, whereas only mannitol (86%) and glutathione (90%) almost completely inhibited DNA damage when added after sonication. SOD and catalase had only a partial inhibitory effect when added after sonication (49% and 63%, respectively). The prevention of DNA damage was also obtained by an association of subliminal amounts of glutathione (20 mM) and vitamin E (1 I.U./ml). These results suggest that the clastogenic activity generated by sonication of human serum is mediated by oxygen radicals.

Xanthine oxidase activity in bronchoalveolar lavage fluid from patients with chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is a serious respiratory pathology characterized by irreversible limitation of expiratory flow and includes chronic obstructive bronchitis, chronic airflow limitation, and emphysema. To determine whether xanthine oxidase activity increased in the airspaces of COPD patients, we examined bronchoalveolar lavage fluid (BAL) from COPD patients recruited during a 2-year clinical study. Filtered BAL supernatant from COPD patients and healthy nonsmoking controls was examined by fluorometric analysis of DNA unwinding (FADU) and spectrophotometric assays (cytochrome c reduction kinetics and uric acid kinetics). Compared to controls, filtered BAL supernatant of subjects with COPD exhibited a detectable clastogenic activity probably related to superoxide production. The method of BAL preparation as an acellular system strongly suggests that superoxide production may be due to xanthine oxidase activity.

Detection of xanthine oxidase activity products by EPR and HPLC in bronchoalveolar lavage fluid from patients with chronic obstructive pulmonary disease.

Xanthine oxidase (xanthine: oxygen oxidoreductase, EC 1.1.3.22), a molybdenum-containing hydroxylase that produces superoxide and uric acid from purine substrates and molecular oxygen, is involved in the oxidative stress underlying several human pathologies including lung diseases. An enzymatic activity similar to xanthine oxidase was previously reported in bronchoalveolar lavage fluid of patients with chronic obstructive pulmonary disease (COPD-BAL), by fluorometric analysis of DNA unwinding and cytochrome c reduction kinetics. Here we report the detection of xanthine oxidase activity products by electron paramagnetic resonance (EPR) in presence of the spin-trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO) and reversed-phase high-performance liquid chromatography (RP-HPLC) in COPD-BAL (n = 14, average age of patients 65 years, range 38-81) and BAL from healthy nonsmoker controls (n = 6, average age 64 years, range 44-73). Superoxide DMPO adducts were detected in COPD-BAL and in an in vitro system containing xanthine and xanthine oxidase (XA/XO), but not in BAL controls and when superoxide dismutase (SOD, 1000 I.U./ml) was added to COPD-BAL. The HPLC analyses after addition of xanthine showed production of uric acid in COPD-BAL and in the XA/XO system but not in BAL controls. These results support the involvement of xanthine oxidase in the mechanisms of superoxide production by BAL supernatant, which increases oxidative stress in chronic obstructive pulmonary disease.

Osteoprogenitor cells in cell populations derived from mouse and rat calvaria differ in their response to corticosterone, cortisol, and cortisone.

Osteoprogenitors present in cell populations derived from fetal or newborn rat and mouse calvaria differentiate in long term culture and form osteoblastic bone-forming colonies (bone nodules). Previous reports have indicated considerable differences between bone cell populations derived from these two species with regard to their proliferation in response to glucocorticoids. In the present investigation, we have focused on proliferation and differentiation of osteoprogenitor cells in these bone cell populations and evaluated the effect of corticosterone, the principal glucocorticoid of both mouse and rat. Cells were isolated by sequential collagenase digestion from calvaria of newborn (2-5 days) CD-1 mice [mouse calvariae (MC) cells] and term fetal Wistar rats [rat calvaria (RC) cells] and cultured for up to 25 days in alpha-minimal essential medium containing 10% fetal bovine serum (FBS), antibiotics, 50 microg/mL ascorbic acid, and 8-10 mmol/L beta-glycerophosphate. In agreement with previous observations by us and others, corticosterone increased cell growth in RC cell cultures, but inhibited cell growth in MC cultures. In RC cell cultures, corticosterone (1-1000 nmol/L) increased the nodule number in a dose-dependent manner (p < 0.001 for all concentrations above 3 nmol/L) with a maximal effect at 300 and 1000 nmol/L (threefold increase over control). In MC cells, on the other hand, corticosterone (0.3-1000 nmol/L) increased the nodule number only at 30 nmol/L (50%, p < 0.01) but inhibited nodule formation by 33% (p < 0.001) at 1000 nmol/L. In both RC and MC cultures a linear relationship was found between the number of cells plated and number of nodules formed. When cultures were treated with cortisol (30-300 nmol/L), similar effects were observed; the number of nodules dose dependently increased in RC cell cultures and dose dependently decreased in MC cell cultures. Significantly, however, the inactive glucocorticoid cortisone also increased bone nodule formation in RC cell cultures and decreased bone nodule formation in MC cell cultures. Carbenoxolone, which blocks 11 beta hydroxysteroid dehydrogenase and thus prevents conversion of cortisone to cortisol, partially inhibited the cortisone-induced effects on bone nodule formation in both RC and MC cell cultures, indicating that both RC and MC cells can convert inactive glucocorticoids to active metabolites. In conclusion, our results show that the glucocorticoids corticosterone and cortisol inhibit proliferation and differentiation of osteoprogenitors in MC cell cultures but stimulate these processes in rat-derived osteoprogenitors.

Oral vs inhaled asthma therapy. Pros, cons and combinations.

A number of oral and inhaled drugs are available for the long term management of patients with persistent asthma, yet the disease continues to be associated with significant morbidity and mortality. Over the past years, inhaled glucocorticoids have become established as a cornerstone of maintenance therapy because of their demonstrated clinical efficacy, ability to reduce bronchial inflammation and good tolerability. Other inhaled drugs (e.g. sodium cromoglycate, nedocromil, long-acting beta 2 agonists) also play a role in the long term treatment of patients with asthma. However, many patients (especially children and the elderly) find inhalers difficult to use, and poor inhalation technique can affect the amount of drug reaching the lungs and response to therapy. Oral drug administration is simple, but, until recently, oral asthma therapy has primarily consisted of sustained-release theophylline and glucocorticoids. Theophylline has a narrow therapeutic index, necessitating regular monitoring of serum drug concentrations, and long term oral glucocorticoid therapy is associated with potentially serious adverse events including osteoporosis with bone fracture. The recent development of orally administered leukotriene receptor antagonists (e.g. zafirlukast) and 5-lipoxygenase inhibitors (e.g. zileuton) offers novel mechanisms of action and potential solutions to compliance issues associated with regular administration of inhaled asthma therapy. These drugs have demonstrated efficacy as maintenance therapy in patients with asthma and, importantly, lack the adverse effects associated with long term systemic glucocorticoid therapy. Further clinical trials and the increasing use of these new therapies will help to establish the precise role of orally administered leukotriene receptor antagonists and 5-lipoxygenase inhibitors in the long term management of patients with asthma.

Raloxifene effect on frequency of surgery for pelvic floor relaxation.

OBJECTIVE: To assess the effects of raloxifene therapy on the frequency of surgery for pelvic floor relaxation in postmenopausal women. METHODS: This analysis used safety data through 3 years of treatment from three double-masked, placebo-controlled, randomized trials of raloxifene, which included 6926 postmenopausal women with uteri at entry. Studies 1 and 2 enrolled 969 nonosteoporotic, postmenopausal women who were assigned to 30, 60, or 150 mg per day raloxifene or placebo. Study 3 enrolled 5957 osteoporotic, postmenopausal women randomized to raloxifene 60 or 120 mg per day or placebo. Indications for any reported pelvic operations were identified, including procedures performed for pelvic organ prolapse or urinary incontinence. RESULTS: A total of 34 (1.51%) women in the placebo group and 35 (0.75%) raloxifene-treated women underwent surgical procedures for pelvic floor relaxation. The odds ratio (and 95% confidence interval) for pelvic floor repair in women assigned to raloxifene was 0.50 (0.31, 0.81). Thus, raloxifene therapy was associated with a significantly reduced risk for pelvic floor surgery (P <.005). CONCLUSION: Raloxifene does not increase pelvic floor relaxation. An apparent protective effect on pelvic floor function warrants further investigation.

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.

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.

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.

Bronchopulmonary inflammation and airway smooth muscle hyperresponsiveness induced by nitrogen dioxide in guinea pigs.

We investigated whether acute exposure to nitrogen dioxide (NO2) causes major inflammatory responses (inflammatory cell recruitment, oedema and smooth muscle hyperresponsiveness) in guinea pig airways. Anaesthetised guinea pigs were exposed to 18 ppm NO2 or air for 4 h through a tracheal cannula. Bronchoalveolar lavage was performed and airway microvascular permeability and in vitro bronchial smooth muscle responsiveness were measured. Exposure to NO2 induced a significant increase in eosinophils and neutrophils in bronchoalveolar lavage fluid, microvascular leakage in the trachea and main bronchi (but not in peripheral airways), and a significant in vitro hyperresponsiveness to acetylcholine, electrical field stimulation, and neurokinin A, but not to histamine. Thus, this study shows that in vivo exposure to high concentrations of NO2 induces major inflammatory responses in guinea pig airways that mimic acute bronchitis induced by exposure to irritant gases in man.

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.

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)

Hypo-osmolar aerosol induces hyperventilation in chronic non-asthmatic rhinitics.

The effect of a hypo-osmolar aerosol on transcutaneous O2 and CO2 time course (PtcO2, PtcCO2) was investigated in subjects affected by chronic non-atopic rhinitis, without any history of asthmatic symptoms and no airways hyper-responsiveness. Twelve normal subjects and 12 subjects affected by chronic idiopathic rhinitis, who had normal responsiveness to both hypo-osmolar aerosol and methacholine challenge as measured by the decrease in FEV1 (mean FEV1 decrease = 5% and PC20 > 16 mg, respectively) were studied. By means of a transcutaneous mono-electrode, it was possible to study the time course of PtcO2 and PtcCO2 during and after a 5-min inhalation of ultrasonically nebulized distilled water (output 2 ml/min-1). A significant decrease in PtcCO2 and increase in PtcO2 were observed during the challenge in rhinitics as compared with normal subjects [maximum decrease and maximum increase expressed as mean value (+/- SD) were -22% (+/- 6.9) and +12.6% (+/- 7.2), respectively]. No significant changes in either PtcCO2 and PtcO2 were observed after the test. The results of this study suggest that patients affected by idiopathic chronic rhinitis with absence of bronchial hyper-responsiveness may present a hyperventilatory response to the inhalation of hypo-osmolar aerosol; the mechanism of such a response might be due to an upregulation of the irritant receptors of the upper airways.

In-vitro exposure of guinea pig main bronchi to 2.5 ppm of nitrogen dioxide does not alter airway smooth muscle response.

In order to investigate whether the oxidant airborne pollutant nitrogen dioxide (NO2) affects airway smooth muscle responsiveness, the contractile response of guinea pig main bronchi after in vitro exposure to 2.5 ppm of nitrogen dioxide was studied. Main bronchi were cannulated and exposed for 2 or 4 h to a constant flow of either NO2 or air. After exposure, bronchial rings were obtained and placed in a 37 degrees C jacketed organ bath filled with Krebs-Henseleit solution. Concentration-response curves were performed for acetylcholine (10(-9)-10(-3) M), substance P (10(-9)-10(-4) M), and neurokinin A (10(-10)-10(-5) M), and voltage-response curves (12-28 V) were performed for electrical field stimulation. There was no significant difference in either the smooth muscle maximal contractile response, or sensitivity between the bronchi exposed to NO2 and those exposed to air. We conclude that in vitro exposure to 2.5 ppm of NO2 does not alter airway smooth muscle responsiveness in guinea pigs.

Antioxidant activity of carbocysteine lysine salt monohydrate.

BACKGROUND: Reactive oxygen radicals are involved in many respiratory diseases, including chronic obstructive pulmonary disease (COPD). Carbocysteine lysine salt monohydrate (CLS) is a mucoactive drug effective in the treatment of bronchopulmonary diseases characterized by mucus alterations, including COPD. In the present study, the antioxidant activity of CLS was studied in vitro in three different oxygen radical producing systems, i.e. bronchoalveolar lavages (BAL) from patients affected by COPD, ultrasound treated human serum and cultured human lung endothelial cells challenged with elastase. METHODS: BAL, exposed or not to different concentrations of CLS (1.5-30 mM), was assayed for free radical content by fluorometric analysis of DNA unwinding (FADU) or by cytochrome c reduction kinetics. Human serum was treated with ultrasound in the presence or absence of CLS (1.5, 2.5 mM) or N-acetyl cysteine (NAC; 4, 5 mM) and assayed for free radical content by FADU. Human endothelial cells cultured in vitro from pulmonary artery were incubated with elastase (0.3 IU/mL), in the presence or absence of glutathione (GSH; 0.65 mM) or CLS (0.16 mM). The supernatant was tested for cytochrome c reduction kinetics whereas cell homogenates were assessed for xanthine oxidase (XO) content by SDS-PAGE. RESULTS: Results showed that CLS is more effective as an in vitro scavenger in comparison to GSH and NAC. CLS reduced the damage of DNA from healthy donors exposed to COPD-BAL and was able to quench clastogenic activity induced in human serum by exposure to ultrasound at concentrations as low as 2.5 mM. NAC protect DNA from radical damage, starting from 5 mM. In human lung endothelial cells cultured in presence of elastase, CLS (0.16 mM) decreased xanthine oxidase activity. CONCLUSIONS: These results suggest that CLS could act by interfering with the conversion of xanthine dehydrogenase into superoxide-producing xanthine oxidase. The antioxidant activity of CLS could contribute to its therapeutic activity by reducing radical damage to different lung structures.