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Biomedical subjects

L Allegra

Publications and source records attributed to L Allegra.

At least 55 records · Page 3Linked to original sources
PubMed1999

Changes in exhaled carbon monoxide and nitric oxide levels following allergen challenge in patients with asthma.

Carbon monoxide is a product of haem degradation by haem oxygenase (HO), activated by inflammatory cytokines and oxidants. This study examined whether allergen challenge can increase exhaled CO levels, as a reflection of HO activation. Exhaled CO and nitric oxide, an expired gas also thought to reflect cytokine-induced airway inflammation, were measured in 15 atopic steroid-naive nonsmoking patients with asthma (13 males, aged 30+/-2 yrs) before and for up to 20 h after allergen challenge. Baseline CO (4.4+/-0.3 parts per million (ppm)) and NO (20.6+/-1.2 parts per billion (ppb)) levels were elevated in asthmatic as compared with nonsmoking normal volunteers (n = 37, 2.1+/-0.2 ppm and 7.0+/-0.1 ppb, respectively, p<0.05). In 10 patients with a dual response in the forced expiratory volume in one second (FEV1) there was a maximal increase in exhaled CO at 1 h (343+/-7.1%) and at 6 h (69+/-12%, p<0.01), followed by a maximal fall in FEV1 (28+/-9%, p<0.05) at 9 h, whereas the maximal NO increase was observed at 10 h (50.2+/-11.8%). The maximal increase in exhaled CO in single response patients (n = 5) was 30+/-2% during the early asthmatic reaction and 46.3+/-9.2% between 4 and 10 h, followed by a fall in FEV1 (9+/-3%, p>0.05) at 9 h, whereas exhaled NO was not significantly changed. In five patients exhaled CO was not attenuated by inhalation of increasing concentrations of histamine causing a 20% fall in FEV1 (PC20) or its subsequent relief by beta2-agonists. In conclusion, exhaled carbon monoxide is increased during the early and late asthmatic reactions independently of the change in airway calibre, while exhaled nitric oxide is increased only during the late reaction and follows the increase in carbon monoxide and fall in the forced expiratory volume in one second in time.

Adult↗
PubMed1999

Asthma controller therapy: role of antileukotrienes, a new therapeutic class.

Asthma is a chronic disease and should be treated with both controller and reliever drugs. Asthma controller therapy is not used sufficiently widely, probably due to low compliance with inhaled drugs, lack of response in some patients to low-medium doses of inhaled steroids and possible adverse events. This review analyses a new class of antiasthmatic drugs, leukotriene receptor antagonists (antileukotrienes). At present, two antileukotrienes are available in Italy: zafirlukast and montelukast. Antileukotrienes improve symptoms and also inhibit the effects of some of the inflammatory mediators involved in the pathogenesis of asthma; therefore, antileukotrienes may be used in monotherapy. In addition, the oral administration route is an advantage for compliance. Antileukotrienes significantly improve pulmonary function, asthma symptoms and inhaled and oral steroid and short-acting beta 2-agonist use. Moreover, antileukotrienes produce a 50% mean reduction in the incidence of asthma exacerbations compared with placebo. From the economic point of view, asthma controller therapy using antileukotrienes is associated with a > 50% (compared with placebo) reduction in healthcare costs (hospitalization due to asthma exacerbation, healthcare contact and absenteeism from work or school), which globally account for 93% of asthma-related costs. Antileukotrienes are indicated in the treatment of persistent mild-to-severe asthma, seasonal allergic asthma, exercise-induced asthma and aspirin-induced asthma. Antileukotrienes are well tolerated independently of the duration of treatment and the incidence of the observed adverse events is substantially similar to that observed using placebo. Owing to good tolerability and compliance and the economic advantages, these agents may be considered a valid therapeutic option for the control and management of asthma as a chronic disease.

Administration, Inhalation↗
PubMed1999

Beta-thalassemia and pulmonary function.

BACKGROUND AND OBJECTIVE: The survival of patients with beta-thalassemia major and intermedia has improved considerably. This has focused attention on the long-term sequelae of the disease itself and its treatment. The effect of hemosiderosis in major organs (heart, liver, etc) are well-recognized, but the pathophysiology of any lung damage is less clearly understood. We studied lung function changes in 32 patients with beta-thalassemia. DESIGN AND METHODS: Respiratory function tests, CO diffusion and arterial blood gas analysis were performed on 19 patients with beta-thalassemia major (9 F, 10 M) and 13 with beta-thalassemia intermedia (6 M, 7 F). All investigations were performed 24 hours before the patients received a blood transfusion or when they were in a stable state hematologic condition. Echocardiography was performed in all patients and the ejection fraction was employed as a measure of cardiac function. RESULTS: No patient had clinical signs of pulmonary dysfunction. Pulmonary function tests, however, showed a reduction of all main parameters (TLC, FVC, FEV1 and RV) in most patients with beta-thalassemia major, indicating a restrictive type of dysfunction. The pulmonary function of patients with beta-thalassemia intermedia seemed to be preserved. Arterial blood gas values were within the normal range, while in some subjects CO diffusion approached the lower limits of normality. There was no evidence that the observed abnormalities in pulmonary function were secondary to congestive heart failure. INTERPRETATION AND CONCLUSIONS: Iron deposition due to repeated blood transfusions may play a central role in determining lung alterations although the majority of patients are well chelated, suggesting that more than one causal mechanisms could be involved.

Adolescent↗
PubMed1998

The effects of multiple dosing with zileuton on antigen-induced responses in sheep.

In a previous study, a single dose of zileuton (10 mg/kg, po) given 2 h before antigen challenge, had a minimal effect on the antigen-induced early airway response (EAR), although it was effective in blocking the late airway response (LAR). Because our previous data indicated that 5-lipoxygenase (5-LO) products contribute to the severity of the antigen-induced EAR in these animals, we hypothesized that the lack of effect of zileuton on the EAR may have had to do with inadequate tissue levels. Therefore, in this study, we determined if multiple dosing with zileuton, which theoretically could improve tissue levels, would provide protection against the antigen-induced EAR as well as the LAR. Each sheep was used in each of the three trials (> or = 15 days apart), the order of which was randomized. For trial 1, the sheep were treated with zileuton (10 mg/kg in 0.1% methylcellulose, p.o.) once a day for 4 days; for trials 2, the sheep were treated with zileuton (10 mg/kg, p.o.) for 2 days; and, for trial 3, the animals were treated with vehicle (0.1% methylcellulose) for 4 days as in trial 1. In all trials, antigen challenge followed 1 h after the last treatment. In the placebo trial, antigen challenge resulted in characteristic EAR (407 +/- 102%, increase over baseline) and LAR (335 +/- 75%, increase over baseline). The antigen-induced effects were completely blocked by the 4-day treatment (EAR = 24 +/- 3%; LAR = 17 +/- 3%, P < 0.05 vs. placebo). In the 2-day trial, the immediate increase in R1, after antigen challenge was only partially blocked (EAR = 163 +/- 16%, P < 0.10 vs. placebo and P < 0.05 vs. 4-day trial), but the late response was completely blocked (24 +/- 3%). The protection against the EAR obtained with the 4-day treatment was significantly better (P < 0.05) than that obtained with the 2-day treatment. The results of this study show that multiple dosing with the 5-LO inhibitor, zileuton, provides protection against the antigen-induced EAR as well as LAR. The effect on the EAR is dependent on the treatment time, with dosing 4 days before antigen challenge providing a more significant effect than either dosing 2 days before challenge (this study) or on the same day as antigen challenge as was seen by us previously. This effect may be related to increased tissue levels of the drug.

Airway Resistance↗
PubMed1998

Incidence of Chlamydia pneumoniae infection in vertically HIV-1 infected children.

The rate of seroconversion for antibody to Chlamydia pneumoniae was analysed in blood samples of 26 vertically HIV-1 infected children and 14 seroreverter children (HIV-negative children born to HIV-positive mothers) during a 3-year study period. Seroconversion for Chlamydia pneumoniae was found in 13 of 26 HIV-1 infected children and in 1 of 14 in the seroreverter group (P=0.013). A lower mean CD4+ cell count and p24 antigen positivity at enrolment were significantly associated with seroconversion for Chlamydia pneumoniae. Signs and symptoms of acute respiratory infection were recorded in the 30 to 40 days preceding collection of the blood samples showing seroconversion for Chlamydia pneumoniae in 8 of 13 HIV-1 infected children and in the single seroreverter. This study confirms the potential role of Chlamydia pneumoniae in the pathogenesis of respiratory tract infections in HIV-1 infected subjects.

Child, Preschool↗
PubMed1998

Age at symptom onset and distribution by sex and symptoms in patients sensitized to different allergens.

The aim of our study was to analyze the clinical features, particularly the age at symptom onset, of allergic subjects (asthma and/or rhinitis) on the basis of the etiologic elements (sensitization to various allergens). We identified a group of monosensitized patients and a group of polysensitized patients. Within these groups, we identified subgroups of subjects monosensitized to one of the five main allergenic mixes (mites, Gramineae, trees, Parietaria, and Artemisia) and five subgroups of patients sensitized nonexclusively, that is, polysensitized, to the same allergens. The comparison between the two groups and among the various subgroups enabled us to conclude that: 1) mono- and polysensitized patients present some clinical features so different as to constitute two clearly distinct clinical groups 2) analysis of the clinical features associated with the sensitization to a specific allergen brings us to significantly different conclusions when we consider subgroups of monosensitized or polysensitized patients 3) the parameter "age at symptom onset" shows great heterogeneity among both the mono- and the polysensitized subgroups--in particular, the great differences in mean age among the monosensitized subgroups (trees>Artemisia>Parietaria>Gramineae>mites) appear very interesting and are open to various interpretative hypotheses 4) unlike the polysensitized group, in the monosensitized group and subgroups, mean age is similar between men and women and, only for tree- and Parietaria-monosensitive patients, also between asthmatic and rhinitic subjects.

Adolescent↗
PubMed1998

The role of chemotherapy in polymorphonuclear phagocytosis in pneumonia.

The efficacy of the host defense system is a determining factor for the outcome of antimicrobial events in infected patients. The neutrophil granulocyte plays a key role in the lung's defense against bacterial invasion and in the absence of a sufficient attraction of functionally intact neutrophils in the lung, following bacterial challenge, severe pulmonary infection may result. The involvement of phagocytes in pneumonia is well known: infiltration of lung parenchyma by neutrophils occurs within a short time in response to infection and is followed by an influx of monocytes. We investigated the effects of antimicrobial therapy in pneumonia on polymorphonuclear neutrophil (PMN) phagocytosis.

Adult↗
PubMed1998

Effect of atropine on ciliary beat in human upper respiratory tract epithelial cells.

The mucociliary apparatus is a fundamental element among the defensive mechanisms of the airways. In man, average ciliary beat frequency (CBF) has been reported to be between 600 and 1,000 beats/min and does not vary significantly at different sites along the respiratory tract. Ciliary function is altered by numerous factors, including temperature, pH, cigarette smoke, drugs, and alcohol. The aim of the present study was to evaluate whether intravenous (i.v.) infusion of atropine alters CBF. We studied nine patients (six females and three males, mean age 42.9 years) with otosclerosis, a nonrespiratory disease. All patients were scheduled for surgical stapedectomy. In all patients, nasal brushing was performed before and 20 min following i.v. injection of 0.5 mg atropine sulphate. The cellular samples, maintained viable in tissue medium, were observed under a microscope and filmed. A quantitative evaluation of ciliary activity was obtained by playing the film back in slow motion. The mean CBF value prior to atropine infusion in the nine patients studied was 588.12 (+/- 53.29 SD) beats/min. After infusion of atropine, mean CBF was 442.33 (+/- 52.82 SD) beats/min. The mean percentage drop in CBF following atropine infusion was 24.79% (t = 5.82, p < 0.001). Our data show a drop in in vitro CBF following atropine infusion which, presumably, reflects a fall in the in vivo efficacy of mucociliary transport. Atropine treatment determined a loss in CBF that was inversely correlated with increasing age.

Adult↗
PubMed1997

Bacterial adherence in smokers and non-smokers.

Bacterial adherence is thought to be a first important step in the pathogenesis of infection. It is now recognized that bacteria bind to and colonize mucosal surfaces in a highly selective manner via a lock- and key mechanism with complementary receptors on the mucosal surfaces of the host. We studied adherence to buccal cells of a panel of potential respiratory pathogens as Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae and Pseudomonas aeruginosa in 18 smokers and 18 healthy non-smokers. Our results show an increased pneumococcal adherence in smokers compared to that of non-smokers and this may explain the role of smoking as a risk factor in the susceptibility to bacterial pneumonia. The other bacterial species tested do not differ in their adhesion values and probably require previous damage of the mucosa before adhesion 1997 The Italian Pharmacological Society.

Bacterial Adhesion↗
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↗
PubMed1997

Clinical efficacy of a vaccine-immunostimulant combination in the prevention of influenza in patients with chronic obstructive pulmonary disease and chronic asthma.

Influenza is a leading cause of morbidity and mortality in patients with chronic respiratory diseases. This study compares two influenza prevention schemes in patients with chronic obstructive pulmonary disease and chronic asthma. We enrolled 66 patients, distributed as follows: Group A: 32 subjects treated with influenza vaccine; Group B: 34 patients treated with influenza vaccine and bacterial immunostimulant. The rate of influenza episodes was recorded. Hemoagglutination inhibiting antibody titers for vaccine strains H1N1, H3N2, and B were determined at time 0 (prior to vaccination), and on days 30 and 90 following vaccination. We observed a lower rate of influenza episodes in Group B patients (8.82%) compared to Group A (31.25%) (p < 0.05). At day 90 Group B patients presented higher geometric mean antibody titers for strains H1N1 (p = 0.07) and H3N2 (p = 0.08). Bacterial immunostimulants appear as possible adjuvants in the prevention of influenza episodes, and may prolong antibody response to influenza vaccine strains.

Adjuvants, Immunologic↗
PubMed1997

Failure to detect the presence of Chlamydia pneumoniae in sarcoid pathology specimens.

The pathogenesis of sarcoidosis is not yet known. On the basis of seroepidemiological data, an association between Chlamydia pneumoniae infection and sarcoidosis has been suggested, but so far no study has addressed the direct detection of this agent in the affected tissues. The aim of the present study was to detect C. pneumoniae deoxyribonucleic acid (DNA) within sarcoid tissue specimens by means of a two-step polymerase chain reaction. Lung biopsy specimens of 33 patients with histologically confirmed pulmonary sarcoidosis and 21 control lung biopsies or pathology specimens of patients with pulmonary carcinoma or emphysema were retrospectively analysed. A nested polymerase chain reaction was applied using two sets of primers designed to detect a fragment of the 16 strand ribosomal ribonucleic acid (rRNA) gene of C. pneumoniae. The results of the study failed to demonstrate the presence of C. pneumoniae in biopsy specimens of sarcoid tissue and in the control lung biopsies or pathology specimens. Our results, therefore, tend to rule out the possibility of a direct involvement of Chlamydia pneumoniae in the pathogenesis of sarcoidosis.

Adult↗
PubMed1997

A possible association of Chlamydia pneumoniae infection and acute myocardial infarction in patients younger than 65 years of age.

STUDY OBJECTIVES: We conducted a retrospective study on patients with acute myocardial infarction (AMI) and evaluated the incidence and prevalence of Chlamydia pneumoniae infection. METHODS: Sixty-one consecutive patients with AMI aged younger than 65 years were enrolled. Within 24 h of hospital admission, serum samples and pharyngeal swab specimens were obtained from all patients. In 49 of 61 patients, after a mean of 28 days from hospital admission, a second serum sample was drawn. A third serum sample was obtained in 23 of 61 patients. Serologic testing for Chlamydia pneumoniae was performed by a microimmunofluorescence test. We applied a nested-polymerase chain reaction for C pneumoniae DNA detection to pharyngeal swab specimens. Simultaneously, we performed a serologic study for C pneumoniae infection on 61 serum samples obtained from blood donors, matched for age, sex, and smoking habits. RESULTS: Serologic test results for C pneumoniae were consistent with acute reinfection in 12 patients, with chronic infection in 23 patients, and results were negative in 26 patients with AMI. In 3 of 12 patients with acute reinfection pattern and in 3 of 23 patients with chronic infection pattern, C pneumoniae DNA was detected on pharyngeal swab specimens. A significantly higher prevalence of IgG titers was observed in patients with AMI (35/61) compared to blood donors (18/61) (p=0.003). CONCLUSION: Our data confirm the possible role of C pneumoniae infection in coronary heart disease and suggest that reinfection may trigger the onset of AMI.

Antibodies, Bacterial↗
PubMed1996

Comparative safety and efficacy of sparfloxacin in the treatment of acute exacerbations of chronic obstructive pulmonary disease: a double-blind, randomised, parallel, multicentre study.

In a double-blind, placebo-controlled trial, patients with acute exacerbations of chronic obstructive pulmonary disease (COPD) were randomly allocated to oral treatment with sparfloxacin (200 mg loading dose followed by 100 mg once daily) or amoxycillin/clavulanic acid (500 mg/125 mg tds) for a total treatment duration of 7 to 14 days. Patients were evaluable if they had a FEV1/FVC ratio of less than 70% at stable state and presented with a suspected infectious exacerbation defined as increases in dyspnoea, sputum volume and sputum purulence. The primary efficacy variable was the overall success (defined as disappearance or improvement of dyspnoea and reductions in sputum volume and purulence) at end of treatment and follow-up. Overall efficacy was assessed in both the intent-to-treat (728 patients) and the evaluable (351 patients) populations. At the end of treatment and follow-up, success rates were identical for the sparfloxacin (87.3% and 78.7%) and amoxycillin-clavulanic acid (88.8% and 79.8%) treatment groups. Similar figures were found for the intent-to-treat population. The analysis of drug safety was similar for both treatment groups. The most frequently encountered pathogens were Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. Sparfloxacin appeared superior for bacteriological eradication of Haemophilus influenzae, and Moraxella catarrhalis. Sparfloxacin in a single daily dose appears at least as effective as amoxycillin/clavulanic acid in the treatment of patients with acute exacerbations of COPD.

Acute Disease↗