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Biomedical subjects

A L Boner

Publications and source records attributed to A L Boner.

At least 91 records · Page 5Linked to original sources
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↗
PubMed1994

Inhaled formoterol in the prevention of exercise-induced bronchoconstriction in asthmatic children.

The duration and magnitude of the effect of inhaled formoterol (12 micrograms) against exercise-induced bronchoconstriction (EIB) was compared with that of inhaled salbutamol (200 micrograms) and that of placebo in 15 children with asthma and EIB in a double-blind, double-dummy, within-patient, placebo-controlled study. The treatments were given by metered dose aerosol on three different days. The exercise test was performed at the 3rd and the 12th hour after dosing. The magnitude of the blocking effect was assessed both by evaluating the lowest FEV1 reading obtained within an hour after each exercise test and by considering the percent decrease below the baseline FEV1 measured before drug administration. Comparison of the lowest values obtained during the hour after each exercise test shows that formoterol was significantly better than both salbutamol (p = 0.022), and placebo (p = 0.001) in limiting exercise-induced bronchoconstriction after the first exercise test (3 h after dosing), while no difference was observed between salbutamol and placebo (p = 0.198). After the second exercise test (12 h after dosing), formoterol again proved to be more effective than both salbutamol (p = 0.008) and placebo (p = 0.001), and no significant difference was observed between salbutamol and placebo (p = 0.391). The evaluation of the mean percentage decrease in FEV1 confirmed the results in favor of formoterol in both the exercise tests. No adverse effects were reported in any treatment group. The protection against EIB is significantly more prolonged after formoterol than after salbutamol, and persists for 12 h after dosing.

Administration, Inhalation↗
PubMed1994

Effective allergen avoidance at high altitude reduces allergen-induced bronchial hyperresponsiveness.

We studied the effects of reduced allergen exposure on bronchial hypereactivity (BHR) in two groups of asthmatic children allergic to house dust mites (HDM) living at high altitude for 9 continuous mo. In the first group the serum levels of total and HDM-specific IgE showed significant decreases after 3 mo (p < 0.001 and p < 0.02, respectively) and after 9 mo (p < 0.001). Three months after returning home the total IgE levels had increased significantly (p < 0.001). The mean percentage fall in peak expiratory flow after exercise testing improved after 3 and 9 mo (p < 0.05), but it had deteriorated after 3 mo at home (p < 0.01). The methacholine PD20-FEV1 increased after 3 mo (p = 0.001) and further after 9 mo (p < 0.001), with a decrease after the 3-mo period at sea level (p = 0.01). In the second cohort there was a significant increase in HDM PD20-FEV1 after 6 and 9 mo (p < 0.001), with a slight decrease of magnitude of the allergen-induced late reaction. Histamine PD20-FEV1 significantly increased after 6 and 9 mo at high altitude, particularly in the challenges performed after the HDM bronchial provocation (p < 0.01). Our data demonstrate that allergen avoidance in asthmatic children not only decreases nonspecific BHR but also decreases allergen sensitivity, late allergen-induced bronchial reactions, and enhancement of BHR by allergen challenge.

Allergens↗
PubMed1994

Education in asthmatic children.

Several educational programmes have been developed for patients with asthma, in order to promote changes in behaviour and to improve health and quality of life. Such programmes are commonly termed "asthma self-management" programmes. First generation self-management programmes started in the early 1980s and were intended to develop the concept of "partnership" between physician, patient and family, and to teach children the skills necessary to manage asthma at home. As a result of participation in these programmes, children experienced a reduction of emergency room and unscheduled physician visits, and an improvement in their physical and social activities. The need to assess the long-term persistence of self-management skills led to the development of second generation programmes. These programmes will pay more attention to the within-subject assessment of acquisition and application of self-management techniques. Crucial issues, such as decision-making strategies and evaluation of quality of life should also have a prominent role.

Adolescent↗
PubMed1993

Nedocromil sodium vs. sodium cromoglycate pressurized aerosol in the prevention of bronchoconstriction induced by ultrasonic nebulized distilled water in asthmatic children.

To compare the effectiveness of nedocromil sodium (NS) and sodium cromoglycate (SCG), administered by metered dose inhaler (MDI) with a 700 mL holding chamber (Fisonair Fisons UK) in preventing bronchoconstriction induced by inhalation of ultrasonically nebulized distilled water (UNDW), 12 asthmatic children were studied in a randomized, double-blind, placebo-controlled, intrapatient study. Following a baseline challenge with UNDW, the protective effect of NS, SCG, or placebo was evaluated in each subject. Cumulative doses of delivered nebulized water producing a 20% fall in forced expiratory volume in 1 sec (PD20 UNDW) was measured. Mean (+/- SD) PD20 UNDW was 4.83 (+/- 4.84), 10.16 (+/- 7.05), 1.58 (+/- 0.5), and 15.93 (+/- 0.23) respectively, for baseline, and placebo, SCG, and NS-treated groups. A significant (P < 0.05) protection from UNDW induced bronchoconstriction by NS was observed in comparison with placebo, while no such effect was evident when the children were treated with SCG.

Adolescent↗
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

Effect of beclomethasone dipropionate nasal aerosol on serum markers of bone metabolism in children with seasonal allergic rhinitis.

Thirty-nine children with grass pollen hay fever were randomly treated with nasal inhaled beclomethasone dipropionate (BDP) 200 or 400 microg/day or sodium cromoglycate (SCG) 30 mg/day for 2 months during the pollen season. Serum osteocalcin (OC), parathyroid hormone (PTH), total alkaline phosphatase (AP), bone alkaline phosphatase (BAP) and type I collagen telopeptide (ICTP) were measured immediately before, 1 and 2 months after treatment and 1 week after stopping the therapy. No significant changes in OC, PTH, AP, BAP and ICTP serum level occurred within each group. Minor and probably clinically insignificant between group differences were occasionally found. Our study shows that BDP nasal spray has no significant effect on common markers of bone metabolism.

Administration, Intranasal↗
PubMed1993

Influence of allergen avoidance at high altitude on serum markers of eosinophil activation in children with allergic asthma.

A cohort of 12 asthmatic children was followed over several months, during which they moved back and forth from an allergen-free to an allergen-rich environment at high and low altitude, respectively. The children were treated with non-steroidal anti-asthmatic drugs as clinically needed. Histamine PC20-FEV1 was unaltered during the study period, whereas serum levels of eosinophil cationic protein (ECP) and eosinophil protein X (EPX) showed significant changes when the children were exposed to the offending allergens. The total IgE significantly increased during exposure. The serum levels of myeloperoxidase (MPO) as well as of chemotactic factors for both neutrophils and eosinophils were unaltered during allergen exposure. We conclude that the serum markers of eosinophil activity ECP and EPX are sensitive indices of allergen exposure in asthmatic atopic children.

Adolescent↗
PubMed1993

Preliminary study on the effect of broxaterol on bronchial hyperresponsiveness in asthmatic children: influence of allergen exposure.

Increased bronchial hyperresponsiveness (BHR) has been reported in adult asthmatic patients after regular treatment with beta 2-agonists. In this study we evaluated the effect of a 4-weeks treatment period with broxaterol, a new beta 2-agonist, on BHR in asthmatic children living in two different environmental conditions. Two groups of patients, 24 domiciled at sea level, allergen exposed (group 1), and 24 resident at high altitude (Misurina, 1,756 m) in an allergen-free environment (group 2), have been tested. Children were randomly treated with broxaterol 400 micrograms q.i.d. or sodium chromoglycate 10 mg q.i.d. (as control treatment) by the metered dose inhaler for 4 weeks. Pulmonary function tests and methacholine challenge were performed at the beginning and at the end of the study. Throughout the study period a diary card was completed and peak expiratory flow rate (PEFR) was measured three times daily. Forty-two of the patients admitted concluded the study. No significant change was observed in the methacholine PC20 throughout the study period regardless of the type of treatment and/or environment. The amplitude percentage mean of diurnal changes in PEFR during the study period showed no statistically significant differences between treatments or centres, or in the interaction of treatment with centre, time with treatment, time with centre, time with centre and treatment (p > 0.05). Therefore in this pilot study regular treatment with broxaterol for 4 weeks did not cause an increase in BHR in asthmatic children both in conditions of allergen exposure and in an environment free of offending allergens.

Adolescent↗
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↗
PubMed1993

Vocal cord dysfunction in an asthmatic child: case report.

Acute functional narrowing of the glottis frequently leads to an inappropriate diagnosis of asthma. Only 2 cases have been reported of patients with asthma and concomitant vocal cord dysfunction. We present the case of an adolescent boy with asthma, who exhibited a worsening of wheezing and a reduction in peak expiratory flow rate out of proportion to symptoms due to a vocal cord dysfunction.

Adolescent↗
PubMed1993

Comparison of nedocromil sodium and sodium cromoglycate administered by pressurized aerosol, with and without a spacer device in exercise-induced asthma in children.

To compare the effectiveness of nedocromil sodium (NS) and sodium cromoglycate (SCG) administered by metered dose inhaler (MDI) in preventing exercise-induced asthma (EIA), 12 asthmatic children with EIA were studied in a randomized, double-blind, cross-over, placebo-controlled study. NS and SCG were given by MDI alone, and by MDI with a 700 ml spacer device (Fisonair, Fisons, UK), in order to assess the benefit of using such a device. Following a baseline exercise challenge, the protective effect of NS, SCG or placebo was evaluated in each subject. The percentage fall in forced expiratory volume in one second, and percentage protection were measured. NS and SCG provided a significant and comparable protection from EIA, and both were better than placebo. No further improvement was observed after drug administration via the spacer. Both NS and SCG are effective in preventing EIA in children, when administered at the recommended clinical dose, and the use of a spacer for administering the drug provides no advantage if the technique of inhalation is good.

Administration, Inhalation↗
PubMed1992

Reproducibility of late phase pulmonary response to exercise and its relationship to bronchial hyperreactivity in children with chronic asthma.

To determine the reproducibility of the delayed response to exercise and its effect on bronchial hyperreactivity, we had 26 asthmatic children perform treadmill exercise challenge on two occasions 1 week apart. Both challenges were preceded by 2 control days and 1 histamine challenge day, and were followed by another histamine challenge day. Peak expiratory flow rate (PEFR) was measured hourly for 12 hours on each control day and for 12 hours after each exercise or histamine challenge. During the first week, five patients showed a late reaction (PEFR change > 15%) after exercise, which was present in only two of them the following week. These two patients, however, also showed a spontaneous fall > 15% of PEFR from baseline during the other control study days. A similar pattern was seen in two other patients who had a late response during the second exercise challenge but not during the first. No significant change occurred in histamine PC-20 FEV1 between before and after the exercise challenges. An apparent late asthmatic response after exercise challenge may represent a within-day fluctuation in pulmonary mechanics that develops spontaneously in children with asthma.

Aerosols↗
PubMed1992

Comparison of the effects of loratadine and astemizole in the treatment of children with seasonal allergic rhinoconjunctivitis.

The efficacy and safety of a once-daily dose of loratadine 10 mg (5 mg in patients whose body weight was less than or equal to 30 kg) and astemizole 2 mg/10 kg body weight o.d. were compared in a 14-day third-party blind study. Forty-one children (30 boys and 11 girls, aged 6-14 years) with seasonal allergic rhinoconjunctivitis entered the study. The pollen count was monitored throughout the study. A significant improvement (p less than 0.01) in allergy symptoms was observed from the third day for both drugs; there was no significant difference between drugs, although loratadine led to a greater reduction in symptoms. In the astemizole group, the apparently rapid onset of drug action might by explained by reduced pollen exposure. Therapeutic response was excellent/good in 83.3% and 58.8% of the loratadine and astemizole groups, respectively. The results reported by the patients/parents were similar. Nine of the children on astemizole and four children on loratadine complained of side effects; three patients in the astemizole group were withdrawn from treatment because of adverse effects. No abnormal changes in lab values were observed in either group.

Adolescent↗
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↗