The effect of computer decision support on optimizing appropriate dosing of novel oral anticoagulant therapy in the IMPACT-AF study

Background

Guidelines favour use of the non-vitamin K oral anticoagulants (NOACs) over vitamin-K antagonists for stroke prevention in atrial fibrillation (AF). However, studies have shown these agents are being under-dosed relative to the doses recommended in the product labels.

Purpose

To assess the ability of a CDS tool, employed to support management of patients with AF in primary care, to optimize NOAC prescribing.

Methods

The Integrated Management Program Advancing Community Treatment of Atrial Fibrillation (IMPACT-AF) study was a cluster randomized controlled trial that assessed the ability of a CDS tool to optimize care of community-based AF patients. Between September 2014 and December 2016, 203 primary care providers (104 randomized to CDS use, 99 to usual care [UC]) and 1133 of their patients (n=597 CDS, n=548 UC) were enrolled. Among other functions, 9 CDS program rules provided recommendations on NOAC prescribing based upon a given patient's clinical profile, as per product labels. Appropriate NOAC prescribing within the IMPACT-AF study population was compared between patients managed with the CDS versus UC at baseline and 12-months.

Results

Of those patients prescribed a NOAC, a high proportion (approximately 70%) were managed as per NOAC prescribing recommendations at baseline (Fig. 1). At 12 months, this proportion did not appreciably change in the UC arm (Fig. 1). In the CDS arm, an 8.2% absolute/11.8% relative improvement in appropriate NOAC prescribing over baseline was seen at 12-months (Fig. 1).

A comparison of patients at baseline and 12-months within each arm revealed a non-significant decline in the level of appropriate NOAC prescribing in the UC group (p=0.53). In the CDS arm, a significant improvement was observed in appropriate NOAC prescribing over time (p<0.001).

Conclusion

Even prior to any quality improvement efforts, appropriate NOAC prescribing was higher than anticipated in this contemporary cohort of community-based AF patients. At 12-months, significant further improvements were seen in the CDS but not the UC arm. These findings suggest that physician decision support can help enhance appropriate NOAC prescribing in the primary care setting.

Figure 1. Appropriate NOAC prescribing

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Bayer Inc.

A Study of the Optical Band Gap of Lithium Tungsten Trioxide Thin Films

The insertion of lithium (lithiation) into tungsten trioxide results in the formation of the tungsten bronze LixWO3. Polycrystalline, rf sputter deposited thin films of LixWO3 were investigated for their application in Smart Window Devices. The optical band gap studies of these films revealed the narrowing of the intrinsic band gap as a consequence of lithium insertion. The results suggest that the rigid band model, which is generally adopted in interpreting the electronic structure of the tungsten bronzes may not be applicable in Lix WO3.

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.

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.

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.

Mucin expression in peripheral airways of patients with chronic obstructive pulmonary disease

AIMS

To study the expression of mucins in peripheral airways in patients with chronic obstructive pulmonary disease (COPD).

METHODS AND RESULTS

Peripheral lung sections from smokers with COPD (n = 9) and age-matched controls including smokers (n = 11) and lifelong non-smokers with normal lung function (n = 6) were stained with alcian blue, periodic acid-Schiff (PAS) and by immunohistochemistry of mucins (MUC): MUC2, MUC4, MUC5AC, MUC5B and MUC6. Histochemical staining and immunoreactivity of bronchiolar epithelium were graded and the presence or absence of stained mucus in the bronchiolar lumen was evaluated. There were no differences in alcian blue and PAS epithelial staining between the three groups. Intraluminal PAS staining was significantly more frequent among COPD subjects (P < 0.05). The expression of MUC5AC was significantly higher in the bronchiolar epithelium of patients with COPD (P < 0.05). Within the bronchiolar lumen, the predominant mucin was MUC5B. Intraluminal MUC5B was significantly more frequent among COPD patients (P < 0.05).

CONCLUSIONS

COPD is specifically associated with increased expression of MUC5B in the bronchiolar lumen and of the mucin MUC5AC in the bronchiolar epithelium. These changes in mucin production in the peripheral airways may contribute to the pathophysiology of COPD.

COPD increases the risk of squamous histological subtype in smokers who develop non-small cell lung carcinoma

BACKGROUND

Squamous cell carcinoma has a stronger association with tobacco smoking than other non-small cell lung cancers (NSCLC). A study was undertaken to determine whether chronic obstructive pulmonary disease (COPD) is a risk factor for the squamous cell carcinoma histological subtype in smokers with surgically resectable NSCLC.

METHODS

Using a case-control design, subjects with a surgically confirmed diagnosis of squamous cell carcinoma were enrolled from smokers undergoing lung resection for NSCLC in the District Hospital of Ferrara, Italy. Control subjects were smokers who underwent lung resection for NSCLC in the same hospital and had a surgically confirmed diagnosis of NSCLC of any histological type other than squamous cell.

RESULTS

Eighty six cases and 54 controls (mainly adenocarcinoma, n = 50) were enrolled. The presence of COPD was found to increase the risk for the squamous cell histological subtype by more than four times. Conversely, the presence of chronic bronchitis was found to decrease the risk for this histological subtype by more than four times. Among patients with chronic bronchitis (n = 77), those with COPD had a 3.5 times higher risk of having the squamous cell histological subtype.

CONCLUSIONS

These data suggest that, among smokers with surgically resectable NSCLC, COPD is a risk factor for the squamous cell histological subtype and chronic bronchitis, particularly when not associated with COPD, is a risk factor for the adenocarcinoma histological subtype.

Reducing agents inhibit the contractile response of isolated guinea-pig main bronchi

BACKGROUND

Oxidants are involved in many respiratory disorders, including asthma and chronic obstructive pulmonary diseases. Reduced glutathione (GSH), one of the most important antioxidant compounds against oxidant free radicals, is particularly abundant in the respiratory epithelial lining fluid, where its concentration is increased in inflammatory disorders.

OBJECTIVE

We hypothesized that reducing agents may have a direct effect on airway smooth muscle. Therefore, we studied the effects of GSH on airway smooth muscle contractility in guinea-pig main bronchi. In parallel, we evaluated superoxide anion generation associated with in vitro bronchial smooth muscle contraction.

METHODS

Guinea-pig main bronchi were mounted in organ baths filled with Krebs-Henseleit solution. Concentration-response curves to acetylcholine (Ach) (10(-9)-10(-3) M), carbachol (10(-9)-10(-4) M), or histamine (10(-9)-10(-3) M) were performed in the presence or absence of either reduced or oxidized glutathione (GSSG) (10(-5)-10(-3) M). We also evaluated the effects of GSH and GSSG on allergen-induced contraction in main bronchi obtained from ovalbumin-sensitized guinea-pig. Superoxide dismutase (SOD)-inhibited cytochrome c reduction kinetics was performed to evaluate superoxide anion (O2-) production during Ach-induced contraction.

RESULTS

Reduced but not oxidized glutathione significantly decreased smooth muscle contraction induced by Ach, carbachol, and histamine. Similarly, only the reduced form of glutathione attenuated the bronchoconstriction induced by allergen exposure in bronchi from sensitized animals. Finally, SOD-inhibited cytochrome c reduction kinetics demonstrated increased O2- production following bronchial smooth muscle contraction. This production was not affected by epithelium removal.

CONCLUSION

Our findings show that GSH decreases bronchial smooth muscle contraction to different stimuli and that oxidant free radicals are produced during bronchial smooth muscle contraction. We suggest that oxidants are involved in the mechanisms of bronchoconstriction and that reducing agents could be a possible therapeutic option for airway obstruction sustained by bronchospasm.

Nuclear localisation of p65 in sputum macrophages but not in sputum neutrophils during COPD exacerbations

BACKGROUND

Exacerbations represent an important feature of the clinical manifestation and natural history of chronic obstructive pulmonary disease (COPD). Nuclear localisation of p65 is a signal of nuclear factor-kappaB (NF-kappaB) activation. A study was undertaken to evaluate whether NF-kappaB activation is modified in sputum cells during COPD exacerbations.

METHODS

Total and nuclear p65 immunoreactivity was measured by immunocytochemistry in the sputum cells of 11 smokers with moderate COPD during an exacerbation and after 6-8 weeks of clinical stability.

RESULTS

Total sputum cell count was significantly increased during exacerbations from a median (IQR) of 880 (510-1865) to 1914.5 (1065-3205) x 10(3)/ml (p<0.05). The main inflammatory cells in the sputum were neutrophils (83.2 (75.4-92.3)%) and macrophages (14.7 (2.6-21.6)%) and their relative proportion did not change during exacerbations. Nuclear staining for p65 was absent in sputum neutrophils, both during exacerbations and in the stable phase. In contrast, the percentage of macrophages expressing nuclear p65 increased significantly during exacerbations from a median (IQR) of 16 (7-24)% to 41.4 (6-69)% (p<0.05).

CONCLUSIONS

NF-kappaB appears to be activated in sputum macrophages but not in sputum neutrophils during exacerbations of COPD

Slower rise of exhaled breath temperature in chronic obstructive pulmonary disease

In chronic obstructive pulmonary disease (COPD) there is decreased vascularity of the bronchi and inflammation of the airways that may have opposite effects on the regulation of heat loss. Exhaled air temperature increase (delta(e) T) was measured in 23 patients with moderate COPD (18 male, mean age +/- SEM 70 +/- 1 yrs; forced expiratory volume in one second (FEV1) 45 +/- 3%, FEV1/forced vital capacity 54 +/- 4%) and 16 normal volunteers (64 +/- 4 yr) and compared to exhaled nitric oxide (eNO) and inflammatory cells in induced sputum as a marker of airway inflammation. Delta(e) T was measured during a flow- and pressure-controlled single exhalation with a fast-response thermometer. delta(e) T was reduced in patients with COPD (1.86 +/- 0.15 delta C x s(-1)) compared to normal subjects (4.00 +/- 0.26 delta C x s(-1)). There was no difference in delta(e) T between patients treated with inhaled steroids and those who were steroid naïve. Delta(e) T was correlated with eNO (r=0.60) but not with sputum neutrophilia. In COPD patients, delta(e) T was increased (2.26 +/- 0.16 delta C x s(-1)) after the inhalation of 200 microg of albuterol, which is a known vasodilator, indicating that delta(e) T and bronchial blood flow may be correlated. Exhaled temperature increase is reduced in chronic obstructive pulmonary disease patients and is increased by the inhalation of vasodilators and therefore may be related to changes of bronchial blood flow and tissue remodelling.

Pulmonary blastoma: case report in an adult

We present a case of biphasic pulmonary blastoma, a rare primary malignant lung neoplasm, in a 48 year old man. Despite its resection followed by postoperative chemotherapy, the neoplasm recurred and the patient survived only 41 months after the diagnosis.

An unusual case of congenital short trachea with very long bronchi mimicking bronchial asthma

Case reports of a short trachea with early branching of the main bronchi are uncommon. The case is presented of a 64 year old woman with upper airway obstruction due to this anatomical abnormality which caused breathlessness and wheezing that was misdiagnosed (and treated) as bronchial asthma for many years.

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.

Gene expression profile of antithrombotic protein c defines new mechanisms modulating inflammation and apoptosis

Human protein C is a natural anticoagulant factor, and a recombinant activated form of the molecule (rhAPC) is completing clinical evaluation for treatment of severe sepsis. Because of the pathophysiologic role of endothelial dysfunction in severe inflammatory disease and sepsis, we explored the possibility that rhAPC might directly modulate endothelial function, independent of its anticoagulant activity. Using broad transcriptional profiling, we show that rhAPC directly modulates patterns of endothelial cell gene expression clustering into anti-inflammatory and cell survival pathways. rhAPC directly suppressed expression of p50 and p52 NFkappaB subunits, resulting in a functional decrease in NFkappaB binding at target sites. Further, rhAPC blocked expression of downstream NFkappaB regulated genes following tumor necrosis factor alpha induction, including dose-dependent suppression of cell adhesion expression and functional binding of intracellular adhesion molecule 1, vascular cell adhesion molecule 1, and E-selectin. Further, rhAPC modulated several genes in the endothelial apoptosis pathway, including the Bcl-2 homologue protein and inhibitor of apoptosis protein. These pathway changes resulted in the ability of rhAPC to inhibit the induction of apoptosis by the potent inducer, staurosporine. This new mechanistic understanding of endothelial regulation and the modulation of tumor necrosis factor-induced endothelial dysfunction creates a novel link between coagulation, inflammation, and cell death and provides insight into the molecular basis for the efficacy of APC in systemic inflammation and sepsis.

Congenital diaphragmatic hernia in an adult simulating a pleural liposarcoma

We report the case of a 32-year-old man with the onset of exercise-related dyspnea, chest pain and chest radiography simulating a pleural effusion. The computed tomography of the chest showed signs suggesting pleural liposarcoma. Because of these findings, a videothoracoscopy was performed which surprisingly showed the presence in the left pleural space of intrapleural omentum and spleen. This report underlines that the clinical manifestations of Bochdalek hernia in adults are variegate and in most cases preoperative diagnosis is not possible.

Ion pairing between Cl- or ClO4- and alkali metal complexes of ionophore antibiotics in organic solvents: a multinuclear NMR and FT-IR study

The extent of ion pairing in chloride and perchlorate salts was studied by measurement of the Cl- and ClO4- resonances and the observation of the perchlorate stretching frequency by use of nuclear magnetic resonance (NMR) spectroscopy and Fourier transform infrared spectroscopy (FT-IR), respectively, for a variety of ionophores in various solutions and in large unilaminar vesicles (LUVs). The NMR line widths of chloride and perchlorate were larger in solutions containing the neutral ionophores valinomycin (Val) and nonactin (Non) than in solutions containing the negatively charged ionophores nigericin (Nig), lasalocid (Las), and monensin (Mon). The viscosity-corrected perchlorate NMR line widths in solutions containing Val and Las were significantly negatively correlated (r2 > or = 0.99) with the dielectric constant of the solvent. Solvents with low dielectric constants favored ion pair formation. From methanolic solutions containing the Li+, Na+, K+, and Cs+ salts of Cl- and ClO4-, it was determined that the cation with the highest selectivity for the ionophore affords the most ion pairing. A decrease in pH from 7 to 3 had no significant effect on the NMR line widths of chloride and perchlorate in methanolic solutions containing Val, whereas a similar decrease in pH in a methanolic solution containing Mon caused a 2-fold increase in the line widths. The FT-IR difference spectrum of KClO4 in a methanolic solution containing Val showed splitting at the perchlorate stretching frequency. No band splitting was observed in the FT-IR difference spectrum of KClO(4) in methanolic solutions containing Las. The efflux of 35Cl in LUVs containing the neutral ionophore Val followed first-order kinetics with an efflux constant of 1.70 x 10(-3) x min(-1), as determined by 35Cl NMR spectroscopy. The induction of increased membrane permeability in LUVs by the ionophore was determined to be negligible for Val and Nig by fluorescence spectroscopy.

Partial reversibility of airflow limitation and increased exhaled NO and sputum eosinophilia in chronic obstructive pulmonary disease

We investigated the relationship between the reversibility of airflow limitation, the concentration of nitric oxide (NO) in exhaled air, and the inflammatory cells in the sputum of patients with stable chronic obstructive pulmonary disease (COPD). We examined nine normal healthy control subjects and 20 nonatopic patients with COPD. Ten patients had no reversibility of airflow limitation (increase in FEV(1) of < 12% and < 200 ml after 200 microg of inhaled salbutamol), and 10 patients had partial reversibility of airflow limitation (increase in FEV(1) of < 12% but > 200 ml after 200 microg of inhaled salbutamol). Exhaled NO levels were higher in COPD patients with partial reversibility of airflow limitation than in those with no reversibility of airflow limitation (median 24 [interquartile range 15.3 to 32] ppb versus 8.9 [4.6 to 14.7] ppb; p < 0.01). Compared with healthy control subjects, only COPD patients with partial reversibility of airflow limitation had increased concentrations of sputum eosinophils. We conclude that, in patients with stable COPD, even a partial bronchodilator response to inhaled salbutamol is associated with increased exhaled NO and sputum eosinophilia, suggesting that these patients may have a different response to treatment than do those without reversible airflow limitation.

CD8+ve cells in the lungs of smokers with chronic obstructive pulmonary disease

Previous studies have shown an increased number of inflammatory cells and, in particular, CD8+ve cells in the airways of smokers with chronic obstructive pulmonary disease (COPD). In this study we investigated whether a similar inflammatory process is also present in the lungs, and particularly in lung parenchyma and pulmonary arteries. We examined surgical specimens from three groups of subjects undergoing lung resection for localized pulmonary lesions: nonsmokers (n = 8), asymptomatic smokers with normal lung function (n = 6), and smokers with COPD (n = 10). Alveolar walls and pulmonary arteries were examined with immunohistochemical methods to identify neutrophils, eosinophils, mast cells, macrophages, and CD4+ve and CD8+ve cells. Smokers with COPD had an increased number of CD8+ve cells in both lung parenchyma (p < 0.05) and pulmonary arteries (p < 0.001) as compared with nonsmokers. CD8+ve cells were also increased in pulmonary arteries of smokers with COPD as compared with smokers with normal lung function (p < 0.01). Other inflammatory cells were no different among the three groups. The number of CD8+ve cells in both lung parenchyma and pulmonary arteries was significantly correlated with the degree of airflow limitation in smokers. These results show that an inflammatory process similar to that present in the conducting airways is also present in lung parenchyma and pulmonary arteries of smokers with COPD.

Helicobacter pylori and chronic bronchitis

BACKGROUND

Chronic infections such as those caused by Helicobacter pylori, Chlamydia pneumoniae, and cytomegalovirus have been epidemiologically related to coronary heart disease (CHD). Other studies place H. pylori in relation to other extradigestive diseases. We carried out an epidemiologic pilot study to evaluate the prevalence of H. pylori in patients with chronic bronchitis, a respiratory disease characterized by persistent chronic inflammation, in comparison with a matched control group.

METHODS

An enzyme-linked immunosorbent assay IgG test for H. pylori diagnosis was performed in 60 consecutive patients with chronic bronchitis (15 women and 45 men; age range, 50-89 years; mean age, 70.38 years) and in 69 control subjects, well matched for age and social status (19 women and 50 men: age range, 52-90 years; mean age, 71.3 years).

RESULTS

Foty-nine of 60 patients with chronic bronchitis (81.6%) and 40 of 69 subjects in the control group (57.9%) were H. pylori-positive (P = 0.0079). The odds ratio, calculated by simple analysis (3.2) and confirmed by logistic regression analysis (3.399), indicated that H. pylori infection greatly increases the risk of chronic bronchitis.

CONCLUSIONS

To date, CHD is the only convincing association between H. pylori infection and an extradigestive disease. The main conclusion of this pilot study is that H. pylori infection seems to increase the risk of developing of chronic bronchitis. An important step in this field will be to evaluate the possible change in the clinical conditions after successful eradication therapy in H. pylori-positive patients with chronic bronchitis.

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 therapy of bronchial asthma]

Asthma (Greek word that means "breathlessness" or "open-mouth breath") is a chronic inflammatory disorder of the airways, with extensive infiltration of the airway lumen and wall with eosinophils, mast cells, activated T-lymphocytes. Airway inflammation is associated with airway hyperresponsiveness, recurrent episodes of reversible airflow limitation and respiratory symptoms such as wheezing, chest tightness, breathlessness and cough with mucus production. Curiously, asthma worsens particularly at night and in the early hours of the morning. The current consensus on asthma therapy suggests that pharmacological control of asthma can be achieved with antiinflammatory "controller" medications such as inhaled glucocorticoids and cromones. Short-acting bronchodilators act as "reliever" medications and rapidly reverse acute manifestations of asthma. Asthmatic exacerbations require the repetitive administration of inhaled short-acting beta-2-agonist and the early introduction of oral glucocorticoids. Rarely the severity of exacerbation requires the administration of oxygen (that, if available, is not contraindicated), intravenous bronchodilators, glucocorticoids and epinephryne and mechanical ventilation.

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.

CD8+ T-lymphocytes in peripheral airways of smokers with chronic obstructive pulmonary disease

To investigate whether the inflammatory process in peripheral airways is different in smokers who develop symptoms of chronic bronchitis and chronic airflow limitation and in asymptomatic smokers who do not develop chronic airflow limitation, we examined surgical specimens obtained from 16 smokers undergoing lung resection for localized pulmonary lesions. Nine had symptoms of chronic bronchitis and chronic airflow limitation and seven were asymptomatic with normal lung function. In peripheral airways, immunohistochemical methods were performed to identify neutrophils, macrophages, CD4+ and CD8+ T-lymphocytes infiltrating the airway wall, and morphometric methods were used to measure the internal perimeter, the airway wall area, and the smooth muscle area. The number of CD8+ T-lymphocytes and the smooth muscle area were increased in smokers with symptoms of chronic bronchitis and chronic airflow limitation as compared with asymptomatic smokers with normal lung function, while the number of neutrophils, macrophages, and CD4+ T-lymphocytes were similar in the two groups of subjects examined. We concluded that smokers who develop symptoms of chronic bronchitis and chronic airflow limitation have an increased number of CD8+ T-lymphocytes and an increased smooth muscle area in the peripheral airways as compared with asymptomatic smokers with normal lung function, supporting the important role of CD8+ T-lymphocytes and airway remodeling in the pathogenesis of chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease international guidelines

Although chronic obstructive pulmonary disease (COPD) has a public health importance similar to asthma, it has received less attention. The first guideline on the management of COPD was released in 1987 by the American Thoracic Society. In 1992 the Canadian Thoracic Society released its guidelines. In 1995 the European Respiratory Society and the Thoracic Society of Australia and New Zealand released their guidelines and the American Thoracic Society updated and expand its COPD guidelines. All these documents were followed in 1997 by the guidelines developed by the British Thoracic Society. These COPD guidelines show many similarities but also have some interesting differences. The aim of this paper is to review these similarities and discrepancies. Like all guidelines, COPD guidelines suffer from the limited amount of evidence-based medicine supporting them, a limitation that, however, provides a strong stimulus for further research.

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.

Increased VIP-positive nerve fibers in the mucous glands of subjects with chronic bronchitis

The presence and distribution of neuropeptide-containing nerves within bronchial surgical specimens has been investigated in bronchitic (n = 12) and in nonbronchitic subjects (n = 7). Lung tissue, obtained from patients undergoing thoracotomy for limited lung lesions, was processed immediately and analyzed for nerves using the streptavidin-biotin complex peroxidase method with antisera to the neural marker protein gene product 9.5 (PGP 9.5) and the neuropeptides vasoactive intestinal peptide (VIP), substance P (SP), calcitonin-gene related peptide (CGRP). There were no significant differences between the two groups with respect to the density of PGP 9.5-, SP-, or CGRP-positive nerves in both the locations assessed (smooth muscle layer and glands). The density of VIP-positive nerves was significantly higher in the glands of bronchitic than in nonbronchitic subjects. A negative relationship was found between the presence of airway inflammation, as indexed by mononuclear cell tissue infiltration, and the density of PGP 9.5-positive nerves in both smooth muscle and glands. Likewise, a relationship was found between the smoking history (packs/yr and age of onset of smoking) and the density of VIP-positive nerves in glands. These findings support a role for VIP in the hallmark of chronic bronchitis, i.e., sputum production.

Inflammatory cells in the bronchial glands of smokers with chronic bronchitis

To characterize the inflammatory process in the bronchial glands of smokers with chronic sputum production, we examined lobar bronchi from 18 subjects undergoing lung resection for localized pulmonary lesions, all with a history of cigarette smoking. Nine of the subjects had symptoms of chronic bronchitis and chronic airflow obstruction, and nine were asymptomatic, with normal lung function. The number of neutrophils, eosinophils, mast cells, macrophages, CD4+ and CD8+ T-lymphocytes, and the ratio of CD4+ to CD8+ cells were assessed in the bronchial glands, epithelium, and submucosa. Cells were identified through immunohistochemistry. Smokers with symptoms of chronic bronchitis had an increased number of neutrophils (p = 0.01) and macrophages (p = 0.03) and a decreased CD4+/CD8+ ratio (p = 0.01) in the bronchial glands as compared with asymptomatic smokers. Chronic bronchitic smokers also had an increased number of epithelial neutrophils (p = 0.04), whereas the numbers of macrophages and CD4+ and CD8+ T-lymphocytes in the epithelium and submucosa were similar in the two groups of smokers. No differences in numbers of eosinophils or mast cells were observed between bronchitic and asymptomatic smokers in any of the compartments examined. In conclusion, smokers with chronic sputum production have an increased infiltration of neutrophils and macrophages and an increased proportion of CD8+ T-lymphocytes in their bronchial glands, supporting the important role of bronchial-gland inflammation in the pathogenesis of chronic bronchitis.

Subcutaneous emphysema of the chest wall: a case with unusual presentation

Subcutaneous emphysema (SE) is the presence of air or other gas in the subcutaneous tissue and is generally associated with pneumothorax and/or pneumomediastinum. We describe an unusual presentation of SE of the chest wall without radiological evidence of pneumothorax or pneumomediastinum, which aetiopathogenesis remains open to several hypotheses in spite of an accurate clinical study.

Effect of subchronic in vivo exposure to nitrogen dioxide on lung tissue inflammation, airway microvascular leakage, and in vitro bronchial muscle responsiveness in rats

OBJECTIVES

In a previous study on bronchoalveolar lavage fluid from rats exposed in vivo for seven days to 10 ppm nitrogen dioxide (NO2), it has been shown that there is an influx of macrophages into the airways. The present study investigated the effect of seven day exposure to 10 ppm NO2, on: (a) lung tissue inflammation and morphology; (b) airway microvascular leakage; (c) in vitro contractile response of main bronchi.

METHODS

Lung tissue was studied by light microscopy, after fixing the lungs by inflation with 4% formalin at a pressure of 20 cm H2O. Microvascular leakage was measured by extravasation of Evans blue dye in the larynx, trachea, main bronchi, and intrapulmonary airways. Smooth muscle responsiveness was evaluated by concentration-responses curves to acetylcholine (10(-9)-10(-3) M), serotonin (10(-9)-10(-4) M), and voltage-response curves (12-28 V) to electrical field stimulation.

RESULTS

Histology showed an increased total inflammation at the level of respiratory bronchioles and alveoli. No influx of inflammatory cells was found in the main bronchi. A loss of cilia in the epithelium of small airways and ectasia of alveolar capillaries was also found. By contrast, no alterations to microvascular permeability or modification of bronchial smooth muscle responsiveness was found.

CONCLUSIONS

Subchronic exposure to 10 ppm NO2 causes airway inflammation and structural damage, but does not cause any persistent alteration to microvascular permeability or bronchial smooth muscle responsiveness in rats.

Efficacy of topical tuaminoheptane combined with N-acetyl-cysteine in reducing nasal resistance. A double-blind rhinomanometric study versus xylometazoline and placebo

The aim of this study was to functionally evaluate the decongestant effect of a topical intranasal drug (Rhinofluimucil consisting of tuaminoheptane sulphate (CAS 6411-75-2, THS), a vasoconstrictor, combined with N-acetyl-cysteine (CAS 616-91-1, NAC). This was a double-blind randomized study, versus both xylometazoline and placebo. 18 subjects (8M and 10F, aged 20-47 years), unaffected by any rhinitic pathology, underwent anterior rhinomanometry. Following the basal evaluation (T0), subjects were randomly divided into three groups and subjected, in a double-blind manner, to nasal instillations (2 puffs per nostril) of THS/NAC (R), xylometazoline (O) and saline solution (P), respectively. Rhinomanometry was repeated after 5, 10 and 20 min (T5, T10, T20). Resistance and flow were measured in both nostrils at a pressure gradient of 150 Pa. After R and O nasal resistance significantly decreased from 0.30 Pa to 0.19 Pa and from 0.31 Pa to 0.17 Pa, respectively, and flow significantly increased; no effects were observed with placebo. In this study, THS/NAC showed rapid decongestant properties, with a significant decrease of resistance and increase of inspiratory flow. The same finding was observed with xylometazoline, but not with the placebo. The decongestant effect was rapid: it could already be observed at T5, and remained constant up to T20 without any rebound effect.

Methotrexate in the treatment of systemic glucocorticoid-dependent severe persistent asthma: a word of caution

Methotrexate should not be prescribed to every systemic glucocorticoid-dependent asthmatic. In fact, while methotrexate may be advantageous in selected patients, every attempt to control asthma with regular anti-asthma agents should be made. Most studies on the effects of methotrexate in the treatment of systemic glucocorticoid-dependent asthmatics include small numbers of patients and are all of relatively short duration. Thus, large long-term multicentre trials are urgently needed. In these studies, a uniform accepted definition of systemic glucocorticoid-dependent asthmatics should be used. For the time being, we reinforce the recommendation of the NHLBI/ WHO panel that methotrexate and other systemic glucocorticoid sparing drugs should be considered experimental medications, and used only in selected patients under the supervision of an asthma specialist with previous experimental experience.

Association between toluene diisocyanate-induced asthma and DQB1 markers: a possible role for aspartic acid at position 57

Toluene diisocyanate (TDI) is the most common cause of occupational asthma in western countries. The aim of this study was to investigate whether genetic factors are involved in toluene diisocyanate-induced asthma. We studied the frequency of human leucocyte antigen (HLA) class II genetic markers in three groups of subjects: 1) subjects with TDI-induced asthma (n = 30); 2) exposed subjects with no history of TDI-induced asthma (n = 12); and 3) normal subjects not exposed to TDI (n = 126). Venous blood samples were collected from the three groups and the polymorphic second exon of DQA and DQB genes was amplified by the polymerase chain reaction (PCR) method. Evaluation of HLA class II gene products in TDI-induced asthma cases showed a positive association with HLA-DQB1 * 0503 and a negative association with HLA-DQB1 * 0501 alleles, which differed at residue 57 for a single amino acid, i.e. aspartic acid in DQB1 * 0503 and valine in DQB1 * 0501. No significant difference was found in the distribution of DQA1 alleles between asthmatics and controls. Our results confirm the hypothesis that HLA-DQB1 * 0503 has a role in conferring susceptibility to TDI-induced asthma and that residue 57 of HLA-DQB1 is a potentially critical location.

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.

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.

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.

Airway eosinophilia in chronic bronchitis during exacerbations

To examine the nature and the degree of airway inflammation in chronic bronchitis during exacerbations, bronchial biopsies and sputum were obtained in 11 subjects with chronic bronchitis examined during an exacerbation, and in 12 subjects with chronic bronchitis examined under baseline conditions. All subjects were nonatopic. Lobar bronchial biopsies were assessed using histochemical and immunohistochemical techniques, and sputum was examined for differential cell counts of leukocytes. Subjects with bronchitis during exacerbations had, on average, 30-fold more eosinophils in their bronchial biopsies than did those examined under baseline conditions (p < 0.001). Although to a lesser extent, the numbers of neutrophils (p < 0.01), T-lymphocytes (CD3) (p < 0.05), VLA-1-positive cells (p < 0.01), and TNF-alpha positive cells (p < 0.05) were also increased during exacerbations. By contrast, the T-lymphocyte subpopulations (CD4 and CD8) and the numbers of macrophages, mast cells, IL-2R-positive cells, and IL-1 beta-positive cells were similar in the two groups of subjects, as well as the percentages of ICAM-1- and E-selectin-positive vessels. Eosinophils were also increased in sputum of subjects with exacerbations when compared with those examined under baseline conditions (p < 0.05). In conclusion, exacerbations of chronic bronchitis are associated with a marked airway eosinophilia and with a milder increase in the number of neutrophils, activated T-lymphocytes, and TNF-alpha-positive cells in the bronchial mucosa.

Pidotimod activity against chronic bronchitis exacerbations

The efficacy of pidotimod ((R)-3-[(S)-(5-oxo-2-pyrrolidinyl) carbonyl]-thiazolidine-4-carboxylic acid, PGT/1A, CAS 121808-62-6) in the management of infectious exacerbations of chronic bronchitis was evaluated in a double-blind, placebo-controlled study in parallel groups over 5 months (60 days of treatment and 90 days of follow-up). The study enrolled 580 patients, of whom 514 could be evaluated. The pidotimod group had fewer and shorter infectious episodes, fewer days of antibiotic therapy and fewer days unable to undertake normal activities. The difference vs. placebo was significant during the follow-up period and, in those subjects with a less severe history, during the treatment period also. Pidotimod was well tolerated.

In vitro exposure to nitrogen dioxide (NO2) does not alter bronchial smooth muscle responsiveness in ovalbumin-sensitized guinea-pigs

The aim of this study was to investigate whether in vitro exposure to NO2 affects responsiveness in ovalbumin-sensitized guinea-pig bronchi. Twenty-three animals were sensitized by three weekly intraperitoneal injections of 1 mg ovalbumin in saline with Freund's adjuvant; twenty-one control guinea-pigs received the diluent alone. From each animal, the two main bronchi were obtained and cannulated, then exposed in vitro to a constant intraluminal flow of: (i) either air or 2.5 ppm NO2 with four spikes of 10 ppm NO2 for 2 h; (ii) either air or 10 ppm NO2 for 4 h. A bronchial ring obtained from each animal before exposure was kept in aerated Krebs-Henseleit solution. Rings from bronchi exposed to air, NO2, or kept in Krebs solution were studied isometrically. We performed overall and non-adrenergic non-cholinergic voltage-response curves to electrical field stimulation, concentration-response curves to acetylcholine and to neurokinin A, followed by administration of 10 mg/ml ovalbumin. We did not find any significant difference in bronchial smooth muscle responsiveness between nonexposed, air-exposed and NO2-exposed bronchi, as well as between bronchi from control and sensitized animals. We conclude that in vitro exposure to NO2 does not alter bronchial smooth muscle responsiveness to either specific or non-specific stimuli.

Structural aspects of airway inflammation in COPD

Descriptions of pathology of chronic bronchitis in the past have been mainly focused on mucous gland hypertrophy, since this was considered the morphologic basis of the disease, but more recent studies have suggested a pathogenetic role for airway inflammation in subjects with chronic bronchitis. In the present review, we briefly summarize the results of these latter studies, which describe the nature of airway inflammation and the state of activation of inflammatory cells in the bronchial mucosa of subjects with chronic bronchitis.

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.

Mechanisms and pathology of occupational asthma

Since the pathogenesis and the pathological features of occupational asthma are similar to those of nonoccupational asthma, the former represents a very useful model for the investigation of the pathogenesis of asthma in general. More than one mechanism may be operative in occupational asthma. Among the mechanisms proposed, immunological mechanisms and airway inflammation play an important role. There is evidence to confirm that T-lymphocyte activation and local accumulation in the bronchial wall of activated eosinophils occurs in asthma of diverse aetiology, i.e. immunoglobulin E (IgE)-mediated, occupational and intrinsic. Neurogenic pathways should be further investigated as a potential mechanism of modulation and amplification of airway inflammation in occupational asthma.

Upregulation of adhesion molecules in the bronchial mucosa of subjects with chronic obstructive bronchitis

To determine whether adhesion molecules and cytokines are upregulated in the bronchial mucosa of chronic bronchitics, we obtained bronchial biopsies in 16 chronic bronchitics, in eight asymptomatic smokers, and in seven normal nonsmoking subjects. Bronchial biopsies were examined by immunohistochemistry to identify the expression of E-selectin and intercellular adhesion molecular-1 (ICAM-1) on vessels and on bronchial epithelium, and the expression of interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF-alpha), neutrophil elastase, and eosinophil cationic protein (EG-2) on cells in the submucosa. Chronic bronchitics had an increased number of E-selectin-positive vessels when compared with both asymptomatic smokers (p < 0.05) and normal subjects (p < 0.01). The numbers of ICAM-1-positive vessels, neutrophils, and IL-1 beta, TNF-alpha-, and EG-2-positive cells were not significantly different in the three groups of subjects examined. When the bronchitic group was divided according to the presence or absence of airway obstruction, the increased number of E-selectin-positive vessels persisted only in bronchitics with airway obstruction, who also had an increased expression of ICAM-1 on basal epithelial cells. We concluded that in the bronchial mucosa of chronic bronchitics with airway obstruction, there is an increased expression of E-selectin on vessels and of ICAM-1 on basal epithelial cells, suggesting the involvement of these adhesion molecules in the pathogenesis of the disease.