Biomedical subjects

A L Boner

Publications and source records attributed to A L Boner.

At least 19 recordsLinked to original sources

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↗

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↗

PubMed1992

Evaluation of the allergenicity of infant formulas in a guinea pig model.

In the present study we evaluated the allergenicity of infant formulas using a guinea pig model. Seven groups of ten guinea pigs each maintained on a diet free of cow milk received either water or pasteurized cow milk (PCM) or a conventional cow milk infant formula (CMF) or whey hydrolysate formula (WHF) to drink. On day 37 all the animals were challenged by intravenous injection with 0.5 mL of supernatant of either PCM or WHF. The reactions to the challenge were expressed as none, mild, severe nonfatal, and fatal. A score ranging from 0 to 3 was assigned to each animal and considered in the statistical analysis; P values are expressed as comparisons to the negative water-fed control group. Animals fed WHF and challenged with WHF (group 1), showed 10% fatal reactions and 50% severe but not fatal reactions (P less than .05). When challenged with PCM (group 2), 40% showed a mild reaction. Cow milk formula-fed animals showed 10% fatal reactions and 70% severe reactions when challenged with WHF (group 3). The same challenge caused 40% severe reactions in animals fed PCM (group 4) (P greater than .05). Animals fed and challenged with PCM (group 5) showed 100% fatal reaction (P less than .01). Animals fed water showed no reaction when challenged with either WHF (group 6) or PCM (group 7). The results suggest that WHF has less anaphylactic sensitizing power than PCM and CMF.

Allergens↗

PubMed1991

Effect of inhaled beclomethasone dipropionate on bronchial hyperreactivity in asthmatic children during maximal allergen exposure.

In this double blind study we evaluated the effect of a 2 months long treatment with inhaled beclomethasone dipropionate (300 micrograms/day) on methacholine responses in asthmatic children, during a period of maximal allergen exposure. Baseline values of methacholine PC20-FEV1 were 0.66 +/- 0.22 mg/mL (mean +/- SEM) in 10 children treated with the active drug and 0.78 +/- 0.21 mg/mL in 10 children treated with placebo. After 1 month of treatment PC20-FEV1 was 1.91 +/- 0.64 and 0.80 +/- 0.33 mg/mL, respectively, in the groups treated with beclomethasone versus placebo. A statistically significant reduction in bronchial hyperreactivity (PC20-FEV1, 5.49 +/- 1.86 mg/mL) but no systemic side effects were observed after 2 months of treatment with beclomethasone dipropionate. This is compared with a PC20-FEV1 of 1.38 +/- 0.52 mg/mL in the placebo group. The results confirm the effect of inhaled corticosteroids in reducing bronchial hyperreactivity, even during a period of maximal allergen exposure.

Allergens↗

PubMed1991

Inhibition of different dosages of oxatomide or placebo on skin prick test and nasal allergen provocation.

In this two-stage, double-blind study, we evaluated the effects of different dosages of oxatomide (1 and 2 mg/kg/day) on nasal provocation and skin reaction wheal induced by grass-pollen challenge. Children with a positive history of allergic rhinoconjunctivitis and positive responses to skin prick test and nasal provocation test to grass pollen were studied out of season. The results obtained with 1 mg/kg/day of oxatomide demonstrated no significant difference in wheal areas and nasal secretion induced by allergen challenge between treated and untreated patients. The administration of 2 mg/kg/day demonstrated a significant suppression in wheal reaction and nasal secretion induced by specific challenge.

Adolescent↗

PubMed1991

Anaphylactic sensitizing power of selected infant formulas.

The purpose of the present study was to evaluate the anaphylactic sensitizing power of cow milk, soy milk, casein hydrolysate, and a new cow collagen soy protein hydrolysate (CCSPH) infant formula in a guinea pig model of anaphylactic sensitization. Various groups of animals were fed these formulas for 37 days following which they were challenged intravenously either with the sensitizing constituent or one of the infant formulations. The results of these studies indicate a high degree of sensitizing capability of cow milk formula (80% fatal and 20% nonfatal) with reactions in guinea pigs challenged with BLG and no reactions when challenged with casein hydrolysate. In animals sensitized to soy formula there were only nonfatal reactions in 30% when challenged with soy protein. Casein hydrolysate and CCSPH were shown to be nonsensitizing. The results of these studies support he use of derivative infant formulas for the prevention of cow's milk hypersensitivity in infants.

Allergens↗

PubMed1991

Relationships between skin prick test, radioallergosorbent test, and chemiluminescent assays in allergic children.

The results of skin prick tests (SPT), radioallergosorbent tests (RAST), and multiple chemiluminescent tests (DHS-CLA) to grass mix, parietaria, D. farinae, and D. pteronyssinus were evaluated in 43 allergic children. All CLA tests had valid positive and negative control threads. Chemiluminescent assays class 4 matched with RAST class 3 and/or 4 and CLA class 3 with RAST class 2. The D. farinae, D. pteronyssinus, and grass results obtained with CLA, RAST, and SPT were investigated by principal components analysis that showed a good association between different methods of measuring allergenicity. The results of the present study confirm that DHS-CLA is an effective "in vitro" method for the detection of IgE-allergen specific antibody.

Allergens↗

PubMed1990

Metabisulfite oral challenge: incidence of adverse responses in chronic childhood asthma and its relationship with bronchial hyperreactivity.

Fifty-six children with chronic asthma, 6 to 14 years of age, were studied to evaluate bronchoconstrictive airway responses after ingestion of varying doses of potassium bisulfite administered in one occasion in capsule and in another occasion in solution. With methacholine challenge before and after metabisulfite (MBS) provocation, the relationship of bronchoconstrictive responses and bronchial hyperreactivity was evaluated. Positive bronchoconstrictive responses were observed in only four children after the ingestion of a maximum dose of MBS in capsule and in two children after the ingestion of different doses of MBS solution. A high reactivity to methacholine challenge was present in all the reactive children. After MBS challenge, no additional changes in bronchial reactivity were observed either in the reactors or nonreactors.

Administration, Oral↗

PubMed1990

Double-blind evaluation of effectiveness and safety of flunisolide aerosol for treatment of bronchial asthma in children.

A double-blind study was carried out in 20 asthmatic children in order to evaluate the therapeutic efficacy and safety of inhaled corticosteroid flunisolide. 0.5 mg of the drug was administered by a jet nebulizer twice daily for 2 months. Respiratory symptoms, pulmonary function values and methacholine PC20-FEV1 were evaluated, as also morning cortisol levels, plasma cortisol increase after ACTH test, and 24-h urinary cortisol excretion. The data obtained show the efficacy of the drug in reducing symptoms. No significant difference was observed in pulmonary function values and in bronchial reactivity results between the two groups. No effect of flunisolide was observed on hypothalamic-pituitary-adrenal function. This study confirms the efficacy and safety of flunisolide (0.5 mg b.i.d.) in the treatment of asthmatic children.

Adolescent↗

PubMed1990

Efficacy and duration of action of oral procaterol in asthmatic children after single administration of different dosages.

A double-blind crossover study was performed to evaluate the bronchodilating effect of different single doses of procaterol (less than 0.5 micrograms/kg, 1.5 micrograms/kg, and placebo) orally administered. Sixteen asthmatic children, age 6-12 years, participated in the trial. Pulmonary function, heart rate, blood pressure, and tremor were evaluated at 30, 60, 90, and 120 min and then hourly for 8 hours after administration. All three doses were therapeutically effective. The 1.5 micrograms/kg dose produced a more sustained bronchodilatation effect, but was also associated with an increase in the incidence of tremors. The 0.5 micrograms/kg dosage may, however, be a good starting dose because it assures a reasonable risk/benefit ratio.

Administration, Oral↗

PubMed1990

Additive effect of albuterol and ipratropium bromide in the treatment of bronchospasm in children.

Inhaled albuterol (A) (salbutamol) alone and albuterol plus ipratropium bromide (IB) were administered to 12 asthmatic children. Following administration of A alone or in combination with IB, there was a significant increase in FEV1 and FEF. Significant statistical difference in favor of the association A plus IB was observed at 120 and 240 minutes for FEV1 and in the period 120, 180, and 240 minutes for FEF. The additive effect was present both in the large and small airways. The short-lived additive effect of A plus IB suggests the opportunity to increase the frequency of drug administration in patients with severe bronchial obstruction.

Adolescent↗

PubMed1990

Exercise-induced biphasic responses and methacholine reactivity in asthma.

Biphasic (early and late) asthmatic responses to exercise occurred in seven of 43 children with reproducible exercise-induced asthma. As biphasic allergen-induced asthma is associated with a prolonged increase in nonspecific bronchial hyperreactivity, this effect was not sought in the 43 asthmatic children. There was no significant change in methacholine PD20 FEV1 before and after exercise challenge, either in children who had early, or early and late, exercise responses. Late reactions after allergen exposure are likely to be of considerable clinical significance in relation to the enhancement of bronchial responsiveness. It is reassuring that this is not the case for exercise challenge, as it would have major implications in relation to the recommendations that asthmatics should participate in normal activities and even in training programs. Furthermore, it suggests that there are differences between the pathophysiology of asthma induced by exercise and that produced by allergens.

Adolescent↗

PubMed1990

Theophylline inhibition of BCG-induced pulmonary inflammatory responses.

The present study was performed to evaluate the effect(s) of theophylline on BCG-induced pulmonary inflammatory responses in an experimental rat model system. Five groups of six animals each received the following: group 1: theophylline-treated, BCG-challenged, and sacrificed three days later; group 2: saline-treated, BCG-challenged, and sacrificed three days later; group 3: theophylline-treated, BCG-challenged, and sacrificed five days later; group 4: saline-treated, BCG-challenged, and sacrificed five days later; and group 5: no treatment and no BCG-challenge ("absolute controls"). Quantitative recovery of bronchoalveolar lavage (BAL) cells was performed and compared with histopathologic changes in lung specimens from each animal in all five groups. No significant differences in quantitative BAL cellular recovery were observed in theophylline-treated animals from saline-treated controls. There was a significant reduction in BAL cell number in saline-treated animals sacrificed five days after BCG-challenge (group 4) from that seen in saline-treated animals sacrificed three days after BCG-challenge (group 2). The most striking finding, however, was a marked diminution in granuloma formation induced by theophylline five days after BCG challenge (group 3). These findings suggest an antiinflammatory effect of theophylline.

Animals↗

PubMed1989

Effect of inhaled ipratropium bromide on methacholine and exercise provocation in asthmatic children.

To determine whether doses of ipratropium bromide (IB) greater than those usually administered by aerosol (75-250 micrograms) give a greater degree of protection from exercise-induced asthma (EIA) in children, 12 patients with chronic asthma, ages 7-13 yr, were challenged with methacholine and exercise after inhalation of saline or 125, 250, 500, and 750 micrograms of IB on different days. A small and similar bronchodilation (mean increase over baseline: 5.26%) was observed 60 min after the administration of each dose of IB. IB prevented the bronchoconstriction caused by methacholine in all doses we used without statistically significant differences between them. All doses gave an all-or-none protection from EIA. Mean percent fall in FEV1 after exercise was 36.8, 18.3, 23.7, 27.1, and 23.2 following inhalation of saline or 125, 250, 500, or 750 micrograms of IB, respectively. The degree of protection from EIA was not correlated with the bronchodilation caused by IB. We suggest that muscarinic mechanisms are only partly responsible for the pathogenesis of EIA in children. Their importance varies among subjects and also may be variable in the same subject. Alternative mechanisms may be responsible for bronchoconstriction.

Administration, Inhalation↗

PubMed1989

Efficacy and safety of loratadine suspension in the treatment of children with allergic rhinitis.

The safety and efficacy of loratadine was compared with that of dexchlorpheniramine in children with allergic rhinitis. Twenty-one children received loratadine 0.11-0.24 mg/kg ideal body weight once daily and 19 dexchlorpheniramine 0.10-0.23 mg/kg every 8 h (0.30-0.69 mg/24 h) for 14 consecutive days. Both loratadine and dexchlorpheniramine were effective in reducing nasal and ocular symptoms in allergic children. Substantial improvement in allergy symptoms was observed at the first evaluation (day 3 of treatment) and was maintained for the study duration. No significant trend of abnormality in laboratory parameters was observed. Drowsiness was present only in the dexchlorpheniramine-treated group. Loratadine appears to be a simple, effective and safe therapy for seasonal allergic rhinitis.

Administration, Oral↗

PubMed1989

Changes in bronchial reactivity in asthmatic children after treatment with beclomethasone alone or in association with salbutamol.

Airway inflammation is consistently present in patients with severe asthma. The combination of inhaled steroids and bronchodilators may be useful both for treating symptoms and improving the underlying inflammatory condition. We have compared the effect of beclomethasone dipropionate (BDP) combined with salbutamol (S), BDP alone, and placebo, on the severity of bronchial responsiveness in 30 children with allergic asthma during the period of specific allergen exposure. In children treated with BDP alone, PC20-FEV1 methacholine was 0.66 +/- 0.54 at the beginning and 1.91 +/- 2.11 at the end of the study period (p greater than 0.05). In children treated with BDP + S PC20, methacholine was 1.21 +/- 1.43 at the beginning and 4.22 +/- 3.88 at the end of the study (p less than 0.05). The group of children treated with placebo had a PC20-FEV1 methacholine of 0.79 +/- 0.61 at the beginning of the study and 0.80 +/- 0.46 at the end of the study. The results of the present study show that maintenance treatment with inhaled beclomethasone combined with salbutamol may lead to greater improvement in bronchial hyperreactivity than treatment with inhaled beclomethasone dipropionate alone.

Adolescent↗