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Biomedical subjects

N E Moavero

Publications and source records attributed to N E Moavero.

12 recordsLinked to original sources

Ozone-induced impairment of mucociliary transport and its prevention with N-acetylcysteine.

The effects of an oxidizing gaseous pollutant on tracheal mucous velocity have been studied in conscious sheep. Acute (2 hours) exposure to 1.0 ppm of ozone showed an effect on tracheal mucous velocity that resulted in a significant decrease 40 minutes and 2 hours after exposure (35% and 40% of the baseline, respectively). Repeated exposure for longer periods (4 days, 5 hours/day) to 1.0 ppm of ozone also significantly decreased tracheal mucous velocity during the first and the second day (-47% and -70% of the baseline, respectively), but during the following days of exposure adaptation took place (tracheal mucous velocity ranging from -42% to -55% of baseline). The tracheal mucous velocity still significantly decreased 5 days after the last exposure. N-Acetylcysteine, known both for its mucolytic and antioxidizing properties, has been demonstrated to prevent significantly all of the immediate effects of either short-term or long-term ozone exposures on mucociliary functions.

Acetylcysteine↗

Pleural pressure changes in dogs measured from suprasternal fossa movements.

Movements of the suprasternal fossa during spontaneous breathing monitored with the surface inductive plethysmograph (SIP) have been shown to reflect changes of intrapleural pressure in conscious humans. Calibration of this device in anesthetized intubated dogs was accomplished by adjusting the electrical gain of its analog waveform to be equivalent to changes of airway pressure during inspiratory efforts against an occluded airway. This procedure, denoted the occlusion test, was also used to identify the site of esophageal balloon catheter placement for its recording of intrapleural pressure deflections. The validity of SIP-derived estimates of inspiratory and expiratory pulmonary resistances and lung compliance was established by finding close agreement with measurements obtained with intraesophageal pressure changes during 1) unimpeded spontaneous breathing, 2) inspiratory resistive loading, 3) bronchoprovocation with aerosolized carbachol, 4) mechanical ventilatory modalities, and 5) induced pulmonary edema. Therefore, movements of the suprasternal fossa with respiration can be reliably transformed into quantitative or semiquantitative changes of intrapleural pressure in anesthetized intubated dogs during major alterations of pulmonary mechanics.

Airway Resistance↗

Antitussive activity and respiratory system effects of levodropropizine in man.

Antitussive activity of the new antitussive drug, levodropropizine (S(-)-3-(4-phenyl-piperazin-1-yl)-propane-1,2-diol, DF 526), was evaluated in healthy volunteers by the classical method of citric acid-induced coughing. Levodropropizine dose-dependently reduced cough frequency. Maximal inhibition was observed at 6 h after administration. Cough intensity was also reduced, as shown by the analysis of cough noise. Levodropropizine, at the dosage of 60 mg t.i.d., had no adverse effects on respiratory function nor on airway clearance mechanisms: in fact, it did not affect spirometric parameters. Levodropropizine had no effects on the rheological properties of mucus nor on ciliary activity of airway epithelium.

Adult↗

Smoking, lung function, and body weight.

In a cross-sectional study of steelworkers aged 45-55 years, smokers (n = 105; mean weight 76.1 kg) were found to weigh significantly less than non-smokers (n = 54; 81.6 kg) and ex-smokers (n = 51; 82.6 kg). The lower weight of smokers was attributable to a group with airflow obstruction (n = 37; forced expiratory volume in one second/vital capacity (FEV1/VC) less than 66%), who weighed less (4.8 kg; p less than 0.05) than smokers with normal FEV1/VC (n = 68). In smokers, but not in ex-smokers or non-smokers, body mass index and FEV1/VC ratio were closely related (r = 0.34; p less than 0.001). This association was apparently not due to an effect of body weight on lung function. Weight loss in smokers may be the consequence of impaired lung function or reflect the effect of cigarette smoking on both the respiratory tract and metabolism in susceptible subjects.

Body Weight↗

Changes in lung function after smoking cessation: an assessment from a cross-sectional survey.

Cross-sectional lung function data of 51 ex-smokers (mean, 8 +/- 7 yr since smoking cessation) were compared with those of 54 nonsmokers and 105 current smokers. All subjects were steel workers 45 to 55 yr of age. In order to assess whether lung function indexes improve after smoking cessation, "expected" values were calculated for the ex-smokers, taking into account both duration of smoking and time since cessation. Observed values of forced expiratory volume in one second, vital capacity, residual volume, peak expiratory flow rate, slope of the N2 single-breath washout, and bolus closing volume were significantly different from "expected" ones. This suggested that smoking cessation not only stopped the smoking-induced fast decline in lung function, but even led to some reversal toward nonsmoking values. This was already apparent in 22 subjects who had quit smoking less than 5 yr previously.

Cross-Sectional Studies↗

Significance of small airway tests in middle-aged smokers.

In 54 asymptomatic lifelong nonsmokers and 105 current smokers, all steelworkers 45 to 55 yr of age, we measured several lung function indexes in order to assess the significance of small airway tests, slope of phase III of the N2 single-breath washout (delta N2), and bolus closing volume and closing capacity (CC/TLC). Smokers had all mean indexes significantly different from nonsmokers, with CC/TLC and delta N2 being the most frequently impaired tests. Smokers with small airway disease (abnormal CC/TLC or delta N2) but normal forced expiratory volume in one second (FEV1) vital capacity had a significantly lower FEV1/height3 (p less than 0.001) than subjects without small airway disease. The latter had indexes similar to nonsmokers. Our data suggested that smokers with small airway disease experience a more rapid decline in their FEV1 and thus are more susceptible to long-term smoking than smokers without small airway disease. The later appear to be resistant to tobacco-induced chronic airflow obstruction.

Aging↗

[Study of lung symptomatology and lung function in steelworkers].

We have examined 272 steelworkers, aged 45 to 55 years, by means of the ECSC-questionnaire and the following lung function tests: vital capacity (VC) and forced expiratory volume in one second (FEV1), residual volume (RV) and total lung capacity (TLC); maximal expiratory flow rates (Vmax, Vmax 50, Vmax 75); specific airways conductance (SGaw); slope of the N2 alveolar plateau after oxygen inhalation (delta N2) and the bolus closing volume (CV). The influence of smoking on respiratory symptoms and lung function was confirmed. In order to assess the influence of occupational pollution a sample of 163 workers was classified according to smoking habits and workplace (either LD-steelplant and continuous casting department, or sheet rolling mill). In the nonsmokers group we found that the workers from the steelplant and continuous casting department (n = 12) had a significantly lower SGaw value (delta = 0.065 cm H2O-1 . s-1, p less than 0.01) and a significantly higher CV value (delta = 4.5% VC, p less than 0.05) than the workers from the sheet rolling mill (n = 11). Differences in FEV1/VC, Vmax 50 and Vmax 75 were not significant, but were also consistent with a slight airflow obstruction in the steelplant workers. In the smokers (n = 99) and exsmokers (n = 41) groups no differences existed between both working categories. Our results suggest that nonsmoking workers from the steelplant and the continuous casting department have undergone moderate, but detectable effects from industrial pollution. These effects are probably masked by those of tobacco in smokers and exsmokers.

Air Pollutants, Occupational↗

[Comparative evaluation of the respiratory function and the acid-base equilibrium in patients with chronic bronchopulmonary disease after intravenous administration of 5 beta receptor agonists].

The Authors studied lung mechanics, acid-base balance parameters, arterial blood pressure and pulse rate in five different groups of chronic obstructive lung disease patients, undergoing e.v. different bronchodilators. The drug were: 1. group: 500 gamma of orciprenalina; 2. group: 500 gamma of idrossi-fenil-orciprenalina; 3. group: 200 gamma of salbutamolo; 4. group: 100 gamma of trimetochinolo; 5. group: 500 gamma of terbutalina. The comparative analysis of bronchodilators, their cardiovascular effects and on acid-base balance indicate that mainly salbutamol and trimetochinol have negligeable adverse effects.

Acid-Base Equilibrium↗

Frequency dependence of respiratory resistance in healthy children.

We measured in 130 (61 girls) children aged 3--14 yr respiratory resistance (Rrs), with the oscillation technique, between 4 and 9 Hz. Rrs, at both 4 and 9 Hz, decreased as a function of height (r = 0.74, P less than 0.001). No statistical difference was found between boys and girls. Frequency dependence of resistance (Rrs 4 Hz-Rrs 9 Hz) was found in children at all ages, and decreased with increasing height (r = 0.50, P less than 0.001). We suggest that frequency dependence of resistance in children can be explained on the basis of an increased peripheral resistance, which produces an asynchronous distribution of tidal volume between dead space and lung parenchyma. During growth peripheral resistance decreases and Rrs bcome less frequency dependent to reach at about 15--16 yr independency of frequence.

Adult↗

Aspects of bronchial reactivity to prostaglandins and aspirin in asthmatic patients.

The behaviour of bronchial reactivity to PGF2alpha was studied in asthmatic patients under various experimental conditions. Premedication with aminophylline, i.v., and, to a lesser extent, with DSCG afforded a partial protection, while beclomethasone dipropionate was inactive under this point of view. Diftalone, a new non-steroid anti-inflammatory agent, was well tolerated in 9 aspirin-intolerant asthmatic patients, and did not modify the bronchial response to PGF2alpha which was found to be generally lower then that of other aspirin-tolerant asthmatic patients. PGE 1-2 and DSCG prevented the bronchospasm induced by inhalation or ingestion of acetylsalicylic acid in a small group of patients. Good protection was also reached with PGE1-2 in the exercise-induced bronchospasm.

Adolescent↗

Non-invasive semi-quantitative measurements of tidal pressure-volume and flow relations of lung in COPD patients.

Movement of the suprasternal fossa as detected by surface inductive plethysmography (SIP) has been utilized as a non-invasive means for estimation of intrapleural pressure in the calculation of lung compliance. The purpose of the present study was to ascertain whether pulmonary resistance and work of breathing could also be obtained with SIP. A new calibration procedure based upon substituting values for inspiratory total respiratory resistance measured by forced oscillations into an uncalibrated SIP deflection-flow loop was utilized to convert the SIP waveform to a pressure recording. This permitted estimation of lung compliance, expiratory pulmonary resistance and work of breathing which were then compared to simultaneously measured intraesophageal pressure derived values. Nine seated patients with varying degrees of obstructive airways disease were studied. No differences were found between the SIP and intraesophageal derived group mean values for any parameters, viz inspiratory and expiratory pulmonary resistance, lung compliance and work of breathing. The least variable measurement between the two methods was the work of breathing in which eight of the nine patients had values deviating less than 25% from unity. Values for lung compliance were slightly more divergent and expiratory pulmonary resistance showed large variation. The present investigation indicates that surface inductive plethysmographic detection of suprasternal fossa movement reflects intrapleural pressure swings in a semiquantitative manner; it serves as a non-invasive research technique for estimation of lung compliance, pulmonary resistance and work of breathing.

Adult↗