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Biomedical subjects

G Rolla

Publications and source records attributed to G Rolla.

At least 73 records · Page 4Linked to original sources
PubMed1987

[Respiratory functional decline after 5 years in patients with silicosis and asbestosis].

A retrospective study of 561 patients with silicosis and 234 with asbestosis was performed to assess whether lung function decline in five years is related to the type (restrictive or obstructive) and/or to the degree of initial damage. Based on lung function tests, three groups of patients were identified: NC with normal lung function tests, CR with restrictive impairment and CO with airway obstruction. The degree of impairment was classified as mild, moderate and severe. Patients were considered worse if five years later they presented a higher degree of impairment. The prevalence of CR was significantly higher in asbestosis, that of NC and CO in silicosis (p less than 0.01). Among subjects with normal starting lung function, 9% only developed CR or CO 5 years later. The prevalence of subjects with worsened lung function in the CR groups was significantly higher (p less than 0.001) in asbestotics (36%) than in silicotics (14%) and was closely related to starting functional impairment. In the CO group the prevalence of worsened subjects was significantly higher than in CR (p less than 0.001), similar in the two diseases and independent of starting lung impairment.

Adult↗
PubMed1987

Reduction of histamine-induced bronchoconstriction by magnesium in asthmatic subjects.

The effects of inhaled MgSO4 on histamine bronchoprovocation test (BPT) were studied in nine asthmatics in clinical remission (FEV1 greater than 80% of predicted). Patients performed histamine BPT on 2 separate days, one day after saline and the other after MgSO4 inhalation, in a randomized double-blind design. Spirometry and flow/volume curve were recorded on each test day before and 5 min after NaCl or MgSO4. No significant difference was observed in lung function measurements 2 days before and after either NaCl or MgSO4. The dose of histamine which produced a 20% decrease in control FEV1 (PD20FEV1) was significantly increased by aerosolized MgSO4 (from 0.177 +/- 0.036 mg after NaCl to 0.350 +/- 0.085 after MgSO4, P less than 0.05. After MgSO4 the dose-steps of histamine concentration increased two-fold in two subjects and one-fold in five.

Administration, Inhalation↗
PubMed1987

Effect of verapamil on pulmonary function changes induced by fluid overloading in normal subjects.

The acute effects of the intravenous administration of 10 mg verapamil on pulmonary function changes induced by rapid saline infusion were studied in six normal subjects. Rapid intravenous fluid overloading caused on increase of closing volume (from 6.55 +/- 1.74 to 9.53 +/- 1.77%, p less than 0.05). After verapamil, the closing volume did not increase after infusion in three subjects and the mean increase was not significant (7.08 +/- 1.82 to 8.43 +/- 1.86%). These results suggest that the rapid administration of intravenous verapamil blunts respiratory function abnormalities caused by overhydration interstitial lung oedema.

Adult↗
PubMed1987

Magnesium attenuates methacholine-induced bronchoconstriction in asthmatics.

The effects of inhaled MgSO4 on methacholine bronchoprovocation test (BPT) were studied in 16 asthmatics in clinical remission (FEV1 greater than 80% of predicted). The patients performed methacholine BPT on two separate days, one day after saline, the other day after MgSO4 inhalation, in double-blind cross-over design. Spirometry was recorded on each test day before and 5 min after NaCl or MgSO4. Neither NaCl nor MgSO4 was found to have a significant effect on spirometric measurements. A significant inhibition of reactivity to methacholine was observed with an increase in log PD20 FEV1 from 1.31 +/- 0.11 inhalation units after NaCl to 1.56 +/- 0.11 inhalation units after MgSO4 (p less than 0.01). The most attractive hypothesis to explain the latter, is that Mg2+ might interfere with Ca2+ handling in the bronchial smooth muscle cells similar to that shown for other types of smooth muscle.

Adolescent↗
PubMed1986

[Functional compromise of the small airways in subjects exposed to SiO2].

Aims of our study were: to evaluate small airway function of subjects with past or present silica dust exposure and normal spirometric values; to investigate whether small airway disease is related to radiographic signs of silicosis, to cumulative dust exposure (ES) and to cigarette smoking. Maximal expiratory flow at 50% (MEF50) and 25% (MEF25) of forced expired vital capacity were measured in 112 subjects, 69 with radiographic signs of silicosis, group I, and the remaining 43 with normal chest X-rays. Even if age and ES were significantly higher in group I, no significant difference in respiratory function tests and in prevalence of small airway disease was found between the two groups. In both groups small airway function was significantly negatively related to smoking habits, while it was independent of the other variables considered. Multiple regression analysis with MEF50 and MEF25 as dependent variables did not show any significant relationship. We conclude that small airway disease due to encroachment of bronchiolar walls by SiO2 deposition is masqued by the damage produced by cigarette smoking, even in the presence of radiographic signs of silicosis.

Bronchi↗
PubMed1986

Methacholine inhalation challenge after rapid saline infusion in healthy subjects.

Five healthy subjects were challenged with methacholine on 2 different days, 1 week apart, the second day after acute intravenous 30 ml/kg 0.9% saline infusion. After infusion, we observed a significant reduction in vital capacity (VC), maximal expiratory volume in 1 s (FEV1), provocation dose producing a 35% fall in SGaw (PD35SGaw) and in 25% of maximal expiratory flow (MEF25), and an increase in the slopes of log dose-response curves. Our results suggest an increased bronchial reactivity in acute minimal interstitial lung edema.

Adult↗
PubMed1986

Effect of nifedipine on salbutamol-induced bronchodilation in partially reversible airway obstruction.

The effects of the combination of oral nifedipine (20 mg) and inhaled salbutamol (400 mcg) were studied in ten stable patients with chronic partially reversible airway obstruction in a double-blind crossover design. Specific airway conductance (SGaw), forced expiratory volume in 1 second (FEV1), heart rate and blood pressure were recorded before and 30 min after administration of nifedipine or a placebo and 30, 60, 90, 150, 210 and 270 min after salbutamol inhalation. The mean value of FEV1 30 min after nifedipine was significantly (p less than 0.05) higher than after the placebo. The increase of SGaw and FEV1 produced by salbutamol was not significantly affected by pretreatment with nifedipine at any time. Nifedipine produced a significant increase of the heart rate which persisted throughout the study, but it did not influence blood pressure. No untoward effect was noticed during the study.

Adult↗
PubMed1985

A multivariate analysis of the risk in chronic obstructive lung disease (COLD).

This study was undertaken to assess the validity of cluster analysis for stratifying patients with severe COLD into homogenous subgroups in view of further prospective studies. To this aim, physiological measurements and questionnaire data were obtained from 532 outpatients with severe COLD (e.g. a 1 sec forced expiratory volume (FEV1) below 1.5-1/sec). The model variables selected for the partition in cluster were FEV1, PaO2, response to bronchodilators and heart rate. Two subgroups of patients were identified by the analysis: cluster I with significantly greater physiological impairment than cluster II. The comparison of the prevalences of the variables outside the model between the 2 clusters showed, in fact, that cluster I had a significantly higher prevalence of subjects with heavy smoking (p less than 0.01), prolonged occupational exposure (p less than 0.05), low body weight (p less than 0.05), recent hospitalizations for respiratory troubles (p less than 0.02) and emphysema (p less than 0.01). In conclusion, cluster analysis based on few physiological variables was able to identify, among patients with severe COLD, those with poorer general conditions and higher exposure to specific risk factors, for whom a worse prognosis of life can be expected. The advantages of cluster analysis in comparison to other techniques of classification in this kind of patient is discussed.

Analysis of Variance↗
PubMed1984

Serum angiotensin converting enzyme (ACE) in silicosis.

Circulating Angiotensin Converting Enzyme (ACE) level, chest X-rays and respiratory function tests were determined in 76 male patients with silicosis. Mean serum ACE in the patients was significantly higher than in 30 healthy controls (129.8 +/- 4 U/ml and 92.4 +/- 22.7 respectively), although individual values were in the normal range in about half of the patients. Enzyme levels were independent of silica dust exposure, X-ray changes, functional lung impairment, age, smoking habits, and presence of chronic obstructive pulmonary disease. However, patients with more severe radiological changes tended to have lower ACE values. Our data confirm that serum ACE level is frequently raised in silicosis, but does not give further information in the evaluation of the disease.

Adult↗
PubMed1983

Site of airway obstruction after rapid saline infusion in healthy subjects.

Static and dynamic lung volumes, flow-volume curve in air and after He-O2 were carried out in 5 normal subjects baseline, immediately after rapid infusion of 2 litres of normal saline, and then 15, 30 and 60 min after. At the end of the infusion, a marked reduction of delta MEF50, FVC, FEV1, MEF50, MEF25 and an increase of Viso V and CV/VC were observed in all the subjects. The poor response to He-O2 suggests a predominant increase of small airway resistance after rapid infusion. In the recovery phase, He-O2 tests promptly returned to control values, while an increased CV/VC was detectable until 30 min after the infusion.

Adult↗
PubMed1981

Relation between respiratory function and pulmonary hemodynamics before and after intravenous administration of furosemide in acute myocardial infarction.

Static lung volumes, flow volume curve in air and in a helium-oxygen mixture, PaO2 and pulmonary vascular pressures were measured in 16 patients 2 weeks after uncomplicated acute myocardial infarction and repeated 2 h after furosemide 40 mg i.v. administration. The patients with wedge pressure (WP) greater than 18 mm Hg had significantly lower values of FEV1, FEV1/VC%, MEF40 and MEF 25 in comparison with the patients with WE less than 18 mm Hg. A negative correlation was found between both PAP and WP and MEF25 values (p less than 0.001). After furosemide respiratory function tests improved only in patients with a good hemodynamic response to the drug. PaO2 did not change significantly. Airflow response to helium seemed to be a useful test for determining the site of major bronchial compression.

Adult↗
PubMed1980

Systemic arterial hypertension and small airways function: acute effects of diazoxide and furosemide.

Two groups of 10 patients with systemic arterial hypertension were studied by respiratory function tests before and after acute administration of diazoxide or furosemide. Small airways obstruction was present in a high percentage of patients and was partially reversed after the acute administration either of diazoxide or of furosemide. Systemic arterial hypertension seems to influence small airways caliber, through pulmonary vascular distension and/or pulmonary interstitial edema.

Adult↗
PubMed1980

The in vivo effect of glucose solutions containing Cu++ and Zn++ on the acidogenicity of dental plaque.

A series of experiments were performed to evaluate the lowest concentration of copper or zinc effective in reducing the acidogenicity of dental plaque in vivo when applied simultaneously with a carbohydrate challenge. The effect of a combination of sub-effective concentrations of these metals was also determined. The results showed a significant reduction in acid production in plaque challenged with glucose solutions containing 0.25 mM CuSO4 or 5.0 mM Zn (C2H3O2).2 as compared to glucose solutions alone. Neither 0.1 mM copper sulphate nor 2.5 mM zinc acetate reduced the acidogenicity of plaque significantly, whereas a combination of these subeffective concentrations was effective. The low metal concentrations causing reduction in acid formation in this study may be explained by the inhibiting substances reaching the bacteria at the same time as the substrate. The synergistic effect of the combination of low concentrations of copper and zinc is consistent with the view that these metals effect dental plaque by the same mechanisms.

Acids↗