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Biomedical subjects

D Legnani

Publications and source records attributed to D Legnani.

18 recordsLinked to original sources
PubMed1999

Consecutive epidemics of Q fever in a residential facility for drug abusers: impact on persons with human immunodeficiency virus infection.

Two large outbreaks of Q fever occurred in 1987 and 1988 in an agricultural community for the rehabilitation of drug users. Approximately 40% of the residents were human immunodeficiency virus (HIV)-positive. Two hundred thirty-five residents presented with clinical evidence of a flulike syndrome that was confirmed to be Q fever; moreover, a large proportion of residents developed an asymptomatic infection. Clinical signs and symptoms were rather nonspecific: fever, malaise, and muscle pain that were often associated with pulmonary symptoms. Single or multiple opacities were detected, with mild interstitial inflammation evident on chest roentgenograms. The source of infection was the sheepfold, which is part of the stock-farming activity of the community. Both outbreaks occurred just after lambing had begun. Residents who were exposed during the first epidemic were protected in the second one. The attack rate among HIV-positive residents was significantly higher than that among HIV-negative residents in the first outbreak, whereas only a slight, marginally significant difference was observed in the second outbreak. The clinical features of Q fever did not differ between HIV-positive and HIV-negative individuals. No cases of relapse or chronic disease were observed.

Adult↗
PubMed1997

Respiratory function at different altitudes.

For the evaluation of a respiratory test at high altitude, several factors must be taken into account: the decreased barometric pressure, the decreased density of air and the degree of acclimatization which is related to the altitude and to the length of exposure. Several studies have shown a reduction in forced vital capacity (FVC) at high altitude and using simulated conditions, mainly related to an increase in pulmonary blood volume and development of interstitial edema. To assess the daily spirometric patterns during ascending to high altitudes we studied 17 healthy subjects at both Capanna Regina Margherita on the Italian Alps (4,559 m) and the Pyramid Laboratory in Nepal (5,050 m). Respiratory function tests were performed every day. Peak expiratory flow values significantly increased. The mean percent increase was 15% at 3,200 and 3,600 m and 26% at 4,559 m. FVC and MEF25 values showed a significant decrease (p < 0.005) during the first days above 3,500 m and improved only after several days spent above this altitude. For each subject the maximal reductions in FVC and maximal expiratory flow (MEF) at 25% of FVC however were found on different days. In our opinion, these data support the hypothesis that at high altitude the respiratory function can be affected by the presence of an increased pulmonary blood volume and/or the development of interstitial edema. The observed changes in forced expiration curves at high altitude seem to reflect the degree of acclimatization that is related to the individual susceptibility, to the altitude reached and to the duration of the exposure. These changes are transient and resolve after returning to sea level.

Adult↗
PubMed1997

Bronchial asthma and airway hyperresponsiveness at high altitude.

The mountain climate can modify respiratory function and bronchial responsiveness of asthmatic subjects. Hypoxia, hyperventilation of cold and dry air and physical exertion may worsen asthma or enhance bronchial hyperresponsiveness while a reduction in pollen and pollution may play an important role in reducing bronchial inflammation. At moderate altitude (1,500-2,500 m), the main effect is the absence of allergen and pollutants. We studied bronchial hyperresponsiveness to both hyposmolar aerosol and methacholine at sea level (SL) and at high altitude (HA; 5,050 m) in 11 adult subjects (23-48 years old, 8 atopic, 3 nonatopic) affected by mild asthma. Basal FEV1 at SL and HA were not different (p = 0.09), whereas the decrease in FEV1 induced by the challenge was significantly higher at SL than at HA. (1) Hyposmolar aerosol: at SL the mean FEV1 decreased by 28% from 4.32 to 3.11 liters; at 5,050 m by 7.2% from 4.41 to 4.1 liters (p < 0.001). (2) Methacholine challenge: at SL PD20-FEV1 was 700 micrograms and at HA > 1,600 micrograms (p < 0.005). In 3 asthmatic and 5 nonasthmatic subjects plasma levels of cortisol were also measured. The mean value at SL was 265 nmol and 601 nmol at HA (p < 0.005). We suppose that the reduction in bronchial response might be mainly related to the protective role carried out by the higher levels of cortisol and, as already known, catecholamines.

Adult↗
PubMed1995

High altitude exposure reduces bronchial responsiveness to hypo-osmolar aerosol in lowland asthmatics.

It is well-known that many patients with asthma undergo clinical improvement during a stay at high altitude. At high altitude, the atmospheric and climatic conditions (such as hypoxia, cold and dry air inhalation) could modify the bronchial responsiveness in asthmatics. Our study was designed to assess the difference in bronchial responsiveness to hypotonic aerosol between sea level and high altitudes in nonresident asthmatic subjects. The results were obtained during two mountaineering expeditions above 4,000 m i.e. at 4,559 m on Mt Rosa, Italy; and at 5,050 m near the Mt Everest base camp in Nepal. Eleven mild asthmatics performed standard bronchial challenges with ultrasonically nebulized distilled water (5 min inhalation, delivery 2 mL-min-1) at sea level and after staying at least 72 h at the above mentioned altitudes. The decrease in forced expiratory volume in one second (FEV1) from baseline was used as index of bronchial response. There was no significant difference in pre-challenge FEV1 between sea level and high altitude in either study. However, the bronchoconstriction response to ultrasonically nebulized distilled water was significantly reduced at high altitude in both studies. At sea level the mean FEV1 decrease was 22.2% (range 15-35%), whereas as the maximal altitude it was 6.7% (range 2-11%). Our results indicate that there is a reduction in bronchial responsiveness to hypoosmolar aerosol at high altitude. This suggests that atmospheric and climatic conditions, or physiological adaptations, via mediators such as atrial natriuretic peptide, are beneficial to patients with asthma at high altitude.

Adult↗
PubMed1994

Outbreak of Chlamydia pneumoniae infection in former injection-drug users.

In a retrospective analysis of lower respiratory tract infections in an ex-injection-drug users community, we found an outbreak (April to July 1991) of Chlamydia pneumoniae infection. The epidemic occurred in a group of 26 community members (23 men and 3 women, mean age, 28.9--3 years) living and working together, who underwent acute and convalescent serologic tests for Mycoplasma pneumoniae, Legionella pneumophila, cytomegalovirus, adenovirus, Coxiella burnetii, and Chlamydia pneumoniae. All subjects were submitted to chest radiograph, while sputum and blood cultures were performed in symptomatic patients. Antibodies to C pneumoniae were determined by a microimmunofluorescence test. Among all subjects studied (13 HIV-1 positive and 13 HIV-1 negative), 11 (8 HIV-positive and 3 HIV-negative) developed pneumonia, 2 (1 HIV-positive and 1 HIV-negative) developed pharyngitis, and 2 (1 HIV- positive and 1 HIV-negative) developed flu-like syndromes sustained by C pneumoniae; in 4 subjects (2 HIV-positive and 2 HIV-negative) suffering from flu-like syndrome, no causal agents were found. Seven subjects (one HIV-positive and six HIV- negative) remained asymptomatic without any evidence of infection. The prevalence of antibodies to C pneumoniae in HIV-1-positive subjects observed in a sample of community members was significantly higher than in HIV-1-negative subjects. C pneumoniae seems to be involved in respiratory tract infections in HIV-1-infected subjects. Our data suggest that C pneumoniae should be included in the diagnostic approach of respiratory infections in HIV-infected subjects.

AIDS-Related Opportunistic Infections↗
PubMed1993

Incidence of community-acquired pneumonia caused by Chlamydia pneumoniae in Italian patients.

The incidence of Chlamydia pneumoniae as a cause of community-acquired pneumonia was evaluated in a one-year prospective study in 108 patients with community-acquired pneumonia. The bacteriological diagnosis was based on culture of sputum or bronchial aspirate and examination of acute and convalescent phase sera for Mycoplasma pneumoniae, Legionella pneumophila and Chlamydia pneumoniae. A definitive microbiological diagnosis was obtained in 58 (54%) patients. Chlamydia pneumoniae was the causative agent in 14 patients (13%) on the basis of positive serological tests; in 10 of the 14 patients Chlamydia pneumoniae was also detected by means of an indirect immunofluorescence test using pharyngeal swab specimens. In conclusion, Chlamydia pneumoniae seems to be a common etiological agent of community-acquired pneumonia, as increasingly reported in the last six to seven years.

Adolescent↗
PubMed1993

Chlamydia pneumoniae infection in acute exacerbations of COPD.

Chlamydia pneumoniae, strain TWAR, is a frequent causative agent of acute respiratory disease. We assessed the incidence and prevalence of Chlamydia pneumoniae infections in COPD. We studied, from January 1990 to May 1991, 142 out-patients with acute purulent exacerbations of chronic obstructive pulmonary disease (COPD) and 114 healthy control subjects. Oropharyngeal swab specimens were collected at each exacerbation and analysed using a high definition monoclonal indirect fluorescent antibody test for Chlamydia pneumoniae identification. Immunoglobulins G and M (IgG and IgM) fractions of antibodies to Chlamydia pneumoniae were studied by microimmunofluorescence test. Prevalence of specific IgG was 63% in COPD, and 46% in controls (Chi-squared test p = 0.007). Moreover, mean titre of IgG was significantly higher in COPD than in controls. Five patients were positive for specific IgM (> or = = 1:16), and one had a fourfold increase of IgG titre; four of these patients had been treated with ciprofloxacin 1 g.day-1 for 10 days, and two with erythromycin, 3 g.day-1 for 14 days, with remission of signs and symptoms of exacerbation. Chlamydia pneumoniae identification was always negative. Our data suggest that Chlamydia pneumoniae infection is a rather frequent event in COPD, since at least 4% of exacerbations may be associated with it.

Acute Disease↗
PubMed1992

Comparative clinical and microbiological study of amoxycillin-clavulanic acid and ciprofloxacin in acute purulent exacerbations of chronic bronchitis.

In a retrospective study, the clinical and microbiological efficacy of amoxycillin-clavulanic acid and ciprofloxacin were evaluated in outpatients observed within the previous year who were affected by acute purulent exacerbations of chronic bronchitis. Of the 95 patients included in the trial, 50 received amoxycillin 875 mg-clavulanic acid 125 mg 8-hourly for 10 days and 45 received ciprofloxacin 500 mg 12-hourly before meals for 10 days. Of the amoxycillin-clavulanic acid-treated patients, 90% showed clear clinical improvement and in 10% treatment failed. In the ciprofloxacin group, 75.5% of patients showed improvement and in 24.5% treatment failed. All pathogens isolated prior to therapy were susceptible to the antibiotic used for therapy. At the end of treatment, in the amoxycillin-clavulanic acid-treated group, 84% of strains were eradicated and 8% persisted; others were superinfections. In the ciprofloxacin group, 57.7% of strains were eradicated, 26.6% persisted and 15.5% were superinfections. No clinically significant side effects were observed in either group. Overall, amoxycillin-clavulanic acid demonstrated superior clinical and microbiological efficacy to ciprofloxacin, although this might be attributable to the higher proportion of aerobic Gram-negative pathogens in the ciprofloxacin group.

Adult↗
PubMed1991

Cefaclor in the treatment of infective exacerbations of chronic bronchitis in cigarette smokers.

There is a direct correlation between number of cigarettes smoked and the incidence of lower respiratory tract infection in humans. In studies with smokers suffering from exacerbations of chronic bronchitis, the most common bacterial pathogens found were Haemophilus influenzae, Streptococcus pneumoniae, Staphylococcus aureus and Branhamella catarrhalis. Antibiotics should be effective against such possible pathogens. Cefaclor has demonstrated in vitro activity against all these pathogens. We designed the present study to evaluate the efficacy and safety of cefaclor in the treatment of acute exacerbations of chronic bronchitis in cigarette smokers. A total of 106 patients were enrolled in the study. H. influenzae was the most common bacterial species isolated in the sputum (in 23.6% of the total sample), followed by S. pneumoniae (18.9%), S. aureus (17.0%), K. pneumoniae (7.5%) and B. catarrhalis (5.7%), while mixed forms were present in 22.6% of cases and other pathogens in 4.7%. Cefaclor (500 mg) was given orally every 8h for 7 to 16 days (mean 10.73 +/- 2.11). Analysis of clinical response data indicates that 75.5% of patients were cured and 17.0% improved. This finding is important because it demonstrates that cefaclor's spectrum of activity encompasses all the most likely pathogens encountered in smokers. Because of its excellent response rate, cefaclor is of particular value in the treatment of lower respiratory tract infections in cigarette smokers.

Adult↗
PubMed1988

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↗
PubMedDate not supplied

Role of oral antibiotics in treatment of community-acquired lower respiratory tract infections.

Amoxicillin/clavulanic acid has been one of the first choice treatments for community-acquired lower respiratory tract infection since its introduction nearly 15 years ago. Since then, it has become the "gold standard" against which most new oral antimicrobials are compared, but none of these newer agents has demonstrated a superior efficacy. To the contrary, two recent studies comparing amoxicillin/clavulanic acid with azithromycin, cefixime, or ciprofloxacin in the treatment of acute exacerbations of chronic bronchitis have demonstrated a higher efficacy rate for amoxicillin/clavulanic acid.

Anti-Bacterial Agents↗
PubMedDate not supplied

Pollen, mite and mould samplings by a personal collector at high altitude in Nepal.

The new personal portable sampler for detection of environmental biologic particles (Partrap FA52, Coppa, Biella, Italy) was used to evaluate both atmospheric and indoor biologic particles in bedding at high altitudes during two Italian scientific expeditions in Nepal, in 1994 and 1996 respectively. The sampling was performed outdoors and indoors at the following altitudes: Katmandu 1,330 meters (m), LuKla 2,800 m, Namche 3,500 m, Pericle 4,200 m and Piramide 5,050 m. In both expeditions each sample of outdoor and indoor air was obtained by sucking air into the sampler either against the wind during a 6-h period, from 9 am to 3 pm, or from bedding of inhabitants resident at the different altitudes for 5 min. The number of pollens, moulds and mites trapped in each sample were assessed. The statistical analysis of the results by Spearman correlation test revealed a significant inverse correlation (p < 0.02) between altitude and the number of the considered biologic particles for sampling carried out during both the 1994 and 1996 expeditions. Moreover, Wilcoxon paired test showed no significant difference between the biologic sampling obtained in the two expeditions. These results confirm the decrease of the environmental biologic charge in relation to the increase of altitude and prove the efficacy of Partrap FA52 in obtaining reproducible quantitative data.

Air Pollution↗