PubMed Health⌕ Search

Biomedical subjects

G L Piacentini

Publications and source records attributed to G L Piacentini.

At least 19 recordsLinked to original sources
PubMed1998

Mite-antigen avoidance can reduce bronchial epithelial shedding in allergic asthmatic children.

BACKGROUND: Asthma is characterized by bronchial hyperresponsiveness (BHR), bronchial mucosa inflammation and airway epithelial damage. OBJECTIVE: This study was designed to evaluate the effect of mite avoidance on bronchial epithelial shedding in asthmatic children sensitized to Dermatophagoides. METHODS: The percentages of airway epithelial cells and eosinophil have been counted in samples obtained by hypertonic saline-induced sputum before and after a period of antigen avoidance in an Alpine environment (1756 m). The degree of bronchial hyperresponsiveness to methacholine was also evaluated. RESULTS: After avoidance the median (lower, Q1, and upper, Q3, quartile) percentage of epithelial cells in the sputum decreased significantly from 3.50 [0.50;6.98] to 0 [0;0.5] (P=0.012) and eosinophil percentage decreased from 1 [0;5.25] to 0 [0,1.5] (P<0.05). Median (Q1,Q3) PC20 increased significantly from 2.75 [1.53;7.5] to 3.25 [1.65;15.25] mg/ mL (P=0.038). After 3 weeks of re-exposure to mite the epithelial median (Q1,Q3) percentage raised to 3.90 [1.5;6] (P = 0.027), eosinophils to 1.5 [0;3.00] (NS) and PC20 was 5.25 [1.68;14.50] (NS). CONCLUSION: Exposure to house dust mite antigen can induce airway epithelial shedding even in subjects with low eosinophil airway infiltration, thus supporting the idea that epithelial damage in asthmatics sensitized to Dermatophagoides may be due to a proteolytic activity of the mite major antigens.

Adolescent↗
PubMed1998

Influence of environmental concentrations of NO on the exhaled NO test.

Measurement of levels of exhaled nitric oxide (NO) has been proposed as a noninvasive method for evaluating the degree of airway inflammation in asthmatic patients. Some concern in the interpretation of results of such measurement may arise from possible interference by high environmental concentrations of NO inhaled by these patients. The aim of this study was to verify whether environmental concentrations of NO in the range from 0 to 150 ppb can influence levels of exhaled NO. We tested two groups of subjects. The first group, consisting of 16 subjects, was tested when environmental levels of NO were from 0 to 3 ppb and from 20 to 60 ppb, and exhaled NO mean ppb (+/- SEM) levels were 9.81 +/- 1.43 and 9.78 +/- 1.47 (p = ns) (mean +/- SEM), respectively. The second group, consisting of 30 subjects, was tested at ambient NO concentrations of 0 to 3 ppm, 80 to 100 ppm, and 120 to 150 ppb, and for 18 of these subjects who underwent testing under all three conditions investigated, the mean levels of exhaled NO were 9.23 +/- 1.51, 7.78 +/- 1.19, and 9.33 +/- 1.55 ppb (p = ns), respectively. The results of this study suggest that significantly different ambient levels of NO have no effect on levels of exhaled NO.

Adult↗
PubMed1998

Prevalence of asthma and respiratory symptoms in childhood in an urban area of north-east Italy.

In the present study we have assessed the prevalence of asthma-related symptoms in school children resident in the urban area of Verona, in the north east of Italy, as part of the International Study of Asthma and Allergies in Childhood (ISAAC). The entirely of the population of children aged 6-7 yrs (total 2,350, from 64 schools) and 13-14 years (total 2,500 from 42 schools) living in the area was selected. A questionnaire was distributed at school. This was addressed to the parents of the younger population and distributed directly to the older children. In the two groups 2,091 (89%) and 2,179 (87%) questionnaires were returned, respectively. The results obtained show a more frequent history of "wheeling ever" in the young population compared to the older group (23.2 versus 7.9%, respectively) (p < 0.001). There was no difference in the prevalence of wheezing in the last 12 months (7.3 and 7.4%, respectively), and of asthma (4.6 and 3.5%, respectively). In the older group there was a higher incidence of exercise-induced wheezing (12.0 versus 3.2%), which was particularly significant in the females compared to males (14.2 versus 10.0, respectively; p < 0.01). Our data confirm that there is a marked variation in the prevalence of asthma and asthma-related respiratory symptoms in different centres throughout the world, since we obtained a lower percentage of reported symptoms in comparison to other ISAAC centres.

Adolescent↗
PubMed1997

FEF25-75 as a marker of airway obstruction in asthmatic children during reduced mite exposure at high altitude.

Sensitivity of forced expiratory flow between 25% and 75% of the vital capacity (FEF25-75) in detecting airway obstruction was investigated in 14 children with mild-moderate asthma, allergic to house dust mites, while at high altitude (1756 m). Forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), FEF25-75, and peak expiratory flow (PEF) were measured every 2 weeks for 12 weeks (total, 84 measurements). The presence or absence of wheezing at the chest auscultation was ascertained before each test. During the study period, a significant improvement of both mean (SD) FEF25-75 [61 (12)% vs. 68 (11)% of the predicted value, p = 0.005] and PEF [95 (16)% vs. 103 (13)%, p = 0.002] was observed. FEV1 changed only marginally [82 (7)% vs. 86 (6)%, p = 0.05]. Wheezing was present on 12/84 occasions. Wheezing was associated with abnormal FEF25-75 values on most occasions but not with abnormal FEV1 or PEF. FEF25-75 was decreased on 51% of days in which wheezing was absent. FEV1 and PEF were, respectively, normal in 69% (p < 0.0001) and 92% (p < 0.0001) of measurements in which FEF25-75 was abnormal. These results suggest that FEF25-75 may be considered a good indicator of airflow obstruction and a sensitive marker of respiratory improvement in asthmatic children during reduced antigen exposure.

Adolescent↗
PubMed1996

Influence of allergen avoidance on the eosinophil phase of airway inflammation in children with allergic asthma.

BACKGROUND: Exposure to relevant allergens causes an increase in bronchial hyperresponsiveness, as well as an inflammatory reaction at the site of the bronchial mucosa in patients with asthma. OBJECTIVE: The purpose of this study was to determine whether antigen avoidance can exert an antiinflammatory effect on the eosinophil phase of airway inflammation in children with asthma. METHODS: The level of bronchial hyperreactivity and the percentage of eosinophils in sputum samples obtained by inhalation of hypertonic saline solution, were evaluated in a group of asthmatic children allergic to house dust mite before and after a period of antigen avoidance in an Alpine environment (1756 m). RESULTS: At the end of the avoidance period PC20 increased from a median value (lower and upper quartile: Q1, Q3) of 1.17 (0.74, 4.75) to 3.5 (1.18, 8.87) mg/ml (p = 0.02), and eosinophil percentage in the sputum decreased from a median value (Q1, Q3) of 14.02 (3.34, 28.24) to 2.08 (0, 7.4) (p less than 0.01). CONCLUSION: A 3-month period of antigen avoidance can significantly reduce the eosinophil phase of airway inflammation, along with bronchial hyperresponsiveness, in patients with asthma.

Adolescent↗
PubMed1996

The effect of cetirizine on the integrin-dependent respiratory burst of normodense eosinophils.

It has been proposed that cetirizine inhibits eosinophil migration and adherence. We evaluated the possible effect of cetirizine on integrin-induced eosinophil proinflammatory activation. Normodense eosinophils were triggered with monoclonal antibodies to integrins in the presence of different concentrations of certirizine. Proinflammatory activation was measured by evaluation of O2- production. Only at high concentrations (250 micrograms/ml) and in the first 15 min did certirizine significantly inhibit (p < 0.02) the eosinophil respiratory burst. No effect was shown for lower concentrations (50 and 100 micrograms/ml) or after 15 min. These data suggest that, only at very high concentrations, cetirizine may induce a transient inhibition of the integrin-induced eosinophil respiratory burst.

Antibodies, Monoclonal↗
PubMed1995

Double-blind trial of house-dust mite immunotherapy in asthmatic children resident at high altitude.

Twenty-three Dermatophagoides pteronyssinus (Dpt)-sensitive asthmatic children aged 7-14 years entered a double-blind, placebo-controlled trial of standardized immunotherapy (IT) (Alpare) while resident at high altitude. Dpt sensitivity was evaluated by skin prick tests at different allergen concentrations at the enrollment and after 6 and 12 months of treatment. Bronchial hyperreactivity was evaluated at the same time points, and on each occasion, histamine challenge and, the following day, Dpt bronchial challenge were performed. All patients, irrespective of active treatment, improved clinically and in lung function with increased PC20 and Dpt-PD20. Alpare-treated patients had a significantly decreased sensitivity on Dpt skin testing (P < 0.009) and felt that their asthma had improved (P < 0.001) compared with placebo-treated subjects, but there was no difference between the treatment groups in lung function or bronchial challenge response. IT neither increased nor decreased bronchial histamine sensitivity. Our results indicate that Dpt IT benefits asthmatic children, but improvement by allergen avoidance at high altitude is even greater.

Adolescent↗
PubMed1995

Bronchial reactivity in asthmatic children at high and low altitude. Effect of budesonide.

Inhaled steroids may control bronchial inflammation in asthmatics exposed to allergens. In this study we evaluated whether prophylactic budesonide would prevent relapse of asthma in children re-exposed to offending allergens at sea level, after a period of antigen avoidance at high altitude. Thirty children received either budesonide (200 micrograms b.i.d.) or placebo (double-blind). Following a 4-wk baseline period and 2 wk of treatment at high altitude, children were treated for 3 mo at sea level. Methacholine challenge and pulmonary function studies were performed before and after baseline period, after the 2 wk of treatment in the mountain environment, and at the end of treatment. ECP serum levels were evaluated after the baseline period and at the end of treatment. PEFR and symptoms were recorded in a diary card during the study. The increase in methacholine provocative dosage was greater, although not significant (p = 0.096), in the budesonide than in the placebo group after the treatment at high altitude and remained higher at the end of the treatment (p = 0.04). ECP levels increased in both the groups with no significant difference. Our results confirm that budesonide, in addition to its efficacy in treating pre-existent airway inflammation, is effective in preventing the increase of reactivity in asthmatic children re-exposed to allergens.

Adolescent↗
PubMed1995

Artificial feeding: progresses and problems.

The introduction of infant formulas represents an important result in the field of the newborn and infant artificial feeding, reducing the gap with maternal feeding. In the last decade technological evolution allowed to obtain milk formulas which became more and more similar to human milk starting from cow's milk, thus obtaining a composition adequate to the digestive and nutritional requirements of the newborn and of the infant, starting from the model of the breast feeding (infant formulas). The major differences between human and cow's milk have been corrected by dilution, skimming, addition of carbohydrates, acidification. From an allergenic viewpoint, in a recent study, we observed that no significant differences can be observed in the development of atopic symptoms for children supplemented with different substances in the first 5 days of life or receiving cow's milk infant formulas in the first three months of life, compared to those breast fed. In the case of the development of intolerance or allergy to cow's milk proteins, the substitution of the cow's milk based formula with hydrolysed or soy formulas is required. Maternal feeding represents the best choice for the nutrition of the newborn; however, when it is not possible, milk formulas despite they still show marked differences with human milk, concerning both nutrients and defensive factors, allow to reach satisfactory results about both nutrition and health.

Animals↗
PubMed1994

Benzyl-benzoate foam: effects on mite allergens in mattress, serum and nasal secretory IgE to Dermatophagoides pteronyssinus, and bronchial hyperreactivity in children with allergic asthma.

Home mattresses of 24 asthmatic children with house dust mite allergy were sprayed with either benzyl-benzoate foam or placebo in a double blind fashion, 10 days before the children left the residential house for asthmatic children Istituto Pio XII (located in the Italian Alps in an environment free of mites) and went back to their own home for the Christmas and Easter holidays. A further group of 8 children, whose mattresses received no treatment, was kept as an absolute control. Two days after spraying, benzyl-benzoate or placebo were vacuumed from the mattresses. Acarex test was performed immediately before spraying and at the end of each holiday period of 20 and 10 days, respectively. Bronchial hyperreactivity as well as serum and nasal secretory specific IgE for Dermatophagoides pteronyssinus were assessed in all children immediately before leaving and within 48 hr after returning to the residential house. The results of the study show that sprayed benzyl-benzoate foam was no more effective than placebo in reducing the level of house dust mite recovered from patients' mattresses, or in reducing bronchial hyperreactivity and IgE concentration in serum and nasal secretions.

Adolescent↗
PubMed1994

Changes in nasal specific IgE to mites after periods of allergen exposure-avoidance: a comparison with serum levels.

Variations of serum and nasal specific IgE to Dermatophagoides pteronyssinus (Der p) during alternate periods of antigen avoidance-exposure have been evaluated with an open design in a group of allergic children with asthma and rhinitis at the residential house Istituto Pio XII (Misurina, BL, Italy), at 1756 m, in the Italian Dolomites. A method based on direct incubation of allergen coupled substrate on the nasal mucosa has been employed to evaluate the levels of nasal IgE. Serum specific IgE decreased respectively from (median) 117-89.3 kU/l (P < 0.001) during an initial period of 3 months of allergen avoidance and from 88.2 to 78.4 kU/l (P < 0.0002) during a subsequent period of allergen avoidance. No significant increase in serum specific IgE was, in contrast, observed during two periods, 22 and 9 days, of antigen exposure, changing respectively from 89.3 to 88.2 and from 78.4 to 89.1 kU/l. In contrast, nasal IgE has been significantly influenced by the alternate periods of antigen exposure-avoidance, showing a decrease from 19.75 to 4.01 kU/l (P < 0.0001) after the initial period of avoidance, followed by an increase to 9.95 kU/l (P < 0.0001) after 22 days of exposure. A significant decrease to a value of 2.37 kU/l (P < 0.0001) was also observed during the subsequent period of avoidance, followed again by an increase to 7.87 kU/l (P < 0.002) after 9 days of exposure. The evaluation of the kinetics of changes in nasal specific IgE revealed a significant decrease (P < 0.01) as soon as antigen avoidance was implemented for 3 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Ability of a new infant formula prepared from partially hydrolyzed bovine whey to induce anaphylactic sensitization: evaluation in a guinea pig model.

In the present study we evaluated the allergenicity and immunogenicity of a whey partially hydrolysate formula (PHF) in a guinea pig model. Nine groups of 10 guinea pigs received either a conventional milk formula (CMF) or PHF for 37 days. After intravenous (i.v.) challenge with either beta-lactoglobulin (beta-L) or ultracentrifuged (u)CMF, animals fed CMF showed, respectively, 80% and 100% fatal reactions, whereas animals fed PHF showed no reactions when i.v. challenged both with beta-L and uPHF. Eighty percent fatal reactions, and 10%, respectively, of severe and mild reactions have been observed in the CMF-fed, casein-challenge group. In contrast, only one (10%) mild reaction occurred in the PHF-fed, casein-challenged group. When challenged with u-pasteurized cow's milk (uPCM), CMF-fed animals showed 86% fatal reactions and 14% mild reactions, whereas PHF-fed ones presented 70% no reactions, 20% mild reactions, and one (10%) fatal reaction. Animals fed CMF showed a significantly higher level of specific IgG against cow's milk antigens than PHF-fed ones, which, however, presented higher levels of antibodies than a water-supplemented control group. The present results confirm that PHF is less sensitizing than CMF in a guinea pig model.

Anaphylaxis↗
PubMed1993

Antigen avoidance in a mountain environment: influence on basophil releasability in children with allergic asthma.

BACKGROUND: The influence of natural antigen avoidance in an environment free of relevant allergens (Istituto Pio XII, Misurina, Italian Alps, 1756 m) and of antigen exposure (sea level) on basophil releasability, as well as on bronchial hyperreactivity (BHR) and specific IgE serum level, were investigated in a group of children with asthma who were allergic to Dermatophagoides pteronyssinus. METHODS: Twenty allergic children with asthma participated in the study. Spontaneous and antigen-induced histamine release, BHR, and serum IgE were investigated at the time of admission, after 40 and 80 days of antigen avoidance, and after 15 days of exposure at sea level. RESULTS: Significant drops in antigen-induced basophil histamine release, BHR, and specific IgE serum level but not in spontaneous basophil histamine release were observed after 40 days of antigen avoidance and were confirmed at a further evaluation after 40 more days. After 15 days of antigen exposure at sea level, specific antigen-induced basophil histamine release, BHR, and serum IgE but not spontaneous basophil histamine release increased promptly, even if not significantly. CONCLUSION: In children with allergic asthma, antigen-induced basophil releasability, BHR, and specific IgE serum levels appear to be modifiable by periods of antigen avoidance or exposure.

Altitude↗
PubMed1993

Inhaled corticosteroids in children. Is there a 'safe' dosage?

Inhaled corticosteroids are effective for the treatment of asthma. Because of the appreciation of the importance of airway inflammation in the pathogenesis of the disease, these drugs are being used more frequently not only in severe but also in moderate asthma. Treatment rarely has to be stopped because of topical adverse effects since oropharyngeal candidiasis and dysphonia are uncommon in children. However, paediatricians need to remain alert for the possibility of systemic adverse effects. With sensitive techniques, dose-dependent adrenal suppression has been documented in children treated with inhaled steroids but generally this effect has no clinical relevance. Although suppression of short term growth velocity has been reported, long term studies have shown that when growth impairment occurs in a child with asthma it is more likely to reflect poor asthma control than the administration of inhaled corticosteroids. Calcium supplementation may be necessary in children with asthma treated with inhaled steroids since this treatment may cause reduction in osteocalcin, a marker of osteoblast activity and bone formation. Other systemic adverse effects have been reported in case reports. The use of a large spacer device has been shown to reduce the incidence of both topical and systemic adverse effects from inhaled steroids and their use should be encouraged. In any child with asthma who really needs inhaled steroids, the lowest dose possible should be prescribed; however, the mistake of prescribing doses too low to be therapeutically effective should be avoided.

Administration, Inhalation↗
PubMed1992

Perception of bronchoconstriction in chronic asthma.

Twenty-nine asthmatic children were studied to assess their ability to detect the severity of their bronchoconstriction. First (STEP 0): each child was asked if he "felt asthma," inviting him to give a self-estimated obstruction score (SEOS) from 0 (no asthma) to 3 (severe asthma) and a baseline FEV1 was recorded. Then (STEP 1): methacholine was administered to all except 9 children with an FEV1 less than 80% of predicted who received saline nebulization and a second SEOS was recorded. Finally: salbutamol aerosol was administered and a third SEOS and FEV1 were obtained (STEP 2). Spearman's correlation coefficients r between SEOS and FEV1 were for the overall population -0.602, -0.517, and -0.104 at STEP 0, STEP 1, and STEP 2, respectively. The r values reduction during the trial can be due either to a decrease of children's concentration during the study or to a real difficulty in recognizing repeated changes in airway status. Some children tend to underestimate their bronchospasm. For these patients an accurate assessment of the severity of the bronchoconstriction requires an objective measurement during acute changes in asthmatic children.

Aerosols↗
PubMed1992

Effects of nedocromil sodium on the binding of N-formyl-methionyl-leucyl-phenylalanine in human neutrophils.

In the present study the inhibition by nedocromil sodium of the specific receptor binding of FMLP was evaluated in human neutrophils (PMNs) using a FMLP-(3H) binding assay. The time course of the binding was markedly influenced by nedocromil sodium used at a concentration of 300 microM. No significant inhibition was obtained when the cells were treated with nedocromil sodium 3 microM or with sodium cromoglycate 300 microM. FMLP binding is essentially eliminated by the highest dose of nedocromil sodium. The biologic meaning of this effect in asthmatic patients should be further evaluated.

Anti-Inflammatory Agents, Non-Steroidal↗