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Biomedical subjects

G Vallone

Publications and source records attributed to G Vallone.

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

Reversal of gastric electrical dysrhythmias by cisapride in children with functional dyspepsia. Report of three cases.

Three children (ages 5, 7.6, and 8 years), with recurrent unexplained upper abdominal symptoms such as vomiting, epigastric pain, anorexia, early satiety and without structural or mucosal abnormalities of gastrointestinal tract, underwent electrogastrography (EGG)--recording of gastric electrical activity using cutaneous electrodes positioned on the epigastric region and connected to a recording polygraph. Frequency of EGG signals was analyzed by fast Fourier transform. Significant changes of fasting and fed gastric myoelectrical activity (tachygastria, bradygastria, flatline pattern) were recorded in the three patients; furthermore, gastric emptying (GE) of a solid-liquid mixed meal, measured by ultrasonography, was significantly prolonged in them. A follow-up study was carried out after an eight-week course with oral cisapride: in all patients symptoms improved, GE time normalized, and EGG analysis showed normal electrical rhythm. It is suggested that gastric dysrhythmias can play a pathogenetic role in patients with functional gastrointestinal symptoms and that symptomatic improvement is accompanied by normalization of gastric electrical rhythm.

Child↗
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↗
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

Nedocromil sodium in exercise-induced bronchoconstriction in children.

Twenty asthmatic children were studied in a double-blind within-patient comparative trial designed to assess the efficacy of nedocromil sodium (4 mg) and placebo in exercise-induced bronchoconstriction. The response to exercise challenge given 30 minutes after treatment showed statistically significant differences in favor of nedocromil sodium. No unusual symptoms were reported.

Adolescent↗
PubMed1989

Skin and serum reactivity to some storage mites in children sensitive to Dermatophagoides pteronyssinus.

The incidence of skin test and RAST positivity for Dermatophagoides farinae and storage mites (Glycyphagus privatus, Lepidoglyphus destructor, Tyrophagus putrescentiae, Acarus siro, and Gohieria fusca) have been evaluated in children with bronchial asthma and positive prick test to Dermatophagoides pteronyssinus. The storage mite with highest incidence of skin and RAST positivity was Gohieria fusca, which caused a positive response in more than 50% of the children evaluated. This antigen appears to possess allergenic determinants not present in Dermatophagoides pteronyssinus. The sensitivity to this antigen might be considered in house dust mite-allergic children who do not improve after specific immunotherapy with Dermatophagoides pteronyssinus extracts.

Adolescent↗
PubMed1989

Theophylline levels after single daily and divided dosing of a once-a-day theophylline preparation in asthmatic children.

Twelve children with chronic asthma were treated with a single dose of sustained-release theophylline once-a-day taken after supper at 9 PM. During the steady-state period after 15 days of treatment, serum theophylline levels were measured one and two hours after dosing and then every two hours until 9 PM the following day. The peak concentration (mean +/- SD) of serum theophylline (20.9 +/- 6.5 micrograms/mL) was observed eight hours after dosing while the through concentration (4.34 +/- 2.62 micrograms/mL) was measured 24 hours after dosing; the percent fluctuation (mean +/- SD) was 966.45 +/- 1105.55%. Another 15 children were treated with the same preparation administered at 8 AM after breakfast and at 8 PM after supper. Serum samples for theophylline concentration were obtained immediately before dosing at 8 AM and then every two hours for the following 12 hours. The mean theophylline level observed immediately before dosing at 8 AM was 10.16 +/- 3.84 micrograms/mL while the mean level at 8 PM was 9.39 +/- 4.77 micrograms/mL. The peak serum level was 13.07 +/- 5.13 micrograms/mL at 2 PM, while the trough was 9.31 +/- 3.71 micrograms/mL at 10 AM, with a percent fluctuation of 155.21 +/- 147.95%. Few side effects were seen in both groups. The results of our study clearly demonstrated that in children the percent fluctuation and peak-trough differences are far greater with once daily than with twice daily dosing and this should be considered when planning theophylline treatment in asthmatic children. The administration of a once-a-day preparation every 8-12 hours can however result in overlapping absorption patterns.

Adolescent↗
PubMed1988

Comparison of the protective effect and duration of action of orally administered clenbuterol and salbutamol on exercise-induced asthma in children.

Clenbuterol (C), a long-acting beta 2-selective bronchodilator was compared with salbutamol (S) in exercise-induced asthma (EIA) at two premedication time levels. Sixteen asthmatic children with EIA living at an altitude of 1,750 m were treated with C (0.001 mg/kg) and S (0.12 mg/kg), administered randomly in a double-blind cross-over study 90 and 300 minutes before exercise tests of running on a treadmill for 6 minutes. Pulmonary functions were evaluated prior to the administration of the drugs and immediately before, at the end of, and 2, 5, 10, 15, 20, and 25 minutes after exercise tests. In the preliminary screening exercise test the mean fall of FEV1 was 41.1%, but it was 21.0% and 27.1% after S and 21.9% and 19.9% after C administered 90 and 300 min prior to the test, respectively. Salbutamol administered 300 minutes before the test was statistically less effective than the same drug administered 90 minutes before the test or C administered 300 minutes before the test. Therefore, we can conclude that clenbuterol provides a more lasting protection than salbutamol in EIA.

Administration, Oral↗
PubMed1988

Effect of food on the bioavailability of a slow-release theophylline formulation.

A study was conducted in two groups of healthy volunteers to assess whether the time of administration (10 min before the meal versus 60 min after the meal) influences the pharmacokinetics and absorption kinetics of a slow-release theophylline product (Teonova). In the first group (Group A, n = 10), the drug was given in a paired-sample design as a single dose of 600 mg before and after breakfast with an interval of at least 1 week between the two administrations. In the second group (Group B, n = 10), Teonova was given by the same study design before and after dinner. In all cases, time curves of theophylline plasma levels were determined by collecting serial blood samples 24 h after dosing and analysed pharmacokinetically through model-independent methods. In Group A, curves obtained before and after the meal were fully superimposable, and no difference was found between the pharmacokinetic parameters determined in either condition. The same result was obtained in Group B. Our results indicate that, after single dose, the two different times of administration that we tested were equivalent in pharmacokinetic terms.

Adult↗
PubMed1988

Efficacy and duration of action of placebo responses in the prevention of exercise-induced asthma in children.

Exercise-induced bronchoconstriction, a common phenomenon in asthmatic children, may be prevented by the administration of appropriate drugs. In this study we evaluated the effect and duration of action of placebo (Freon gasses) administered to the patients as a protective drug. The maximum decrease in forced expiratory volume in 1 second (FEV1) after exercise testing was 40.3% +/- 3.10 at the initial screening session and, on different study days, 23.3% +/- 3.57, 28.8% +/- 3.86, and 33.7% +/- 3.71 30, 120, and 240 minutes, respectively, after the administration of Freon gasses. There was a linear trend indicating a reduction in protection with time. The placebo effect was marked 30-120 minutes after treatment (p less than 0.01) and completely disappeared after 4 hours. The placebo effect should always be considered in the evaluation of any new antiasthmatic drug.

Adolescent↗
PubMed1988

[Reliability of intrarectal echography in the staging of the T parameter in carcinoma of the medial and inferior third of the rectum].

The capabilities were evaluated of endorectal ultrasound in assessing the local extension of rectal carcinomas. The study population consisted of 50 patients with histologically proven rectal cancer. A CT scan was also performed on 45 patients, and the results were then compared to postoperative histologic findings. Endorectal US allowed the correct staging of 39/45 tumors (86.6%) with 1 false positive (over-staging T1 as T2), and 5 false negatives (under-staging 3 x T3 as T2; 2 x T4 as T3). CT allowed the correct staging of 37/45 tumors (82.2%), with 5 false positives (overstaging T1 as T2) and 3 false negatives (understaging T3 as T2). Our results prove endorectal US to be a reliable method for the local staging of rectal cancers, limited to mucosa, submucosa and muscular layers of the rectal wall (T1 and T2 tumors). CT does not allow proper evaluation of T1 and T2 tumors, but provides with a better assessment of tumors involving perirectal fat and adjacent structures (T3 and T4). Both CT and endorectal US should, therefore, be used as complementary diagnostic techniques for an accurate evaluation of the local extension of lower rectal cancers.

Humans↗
PubMed1988

Spinhaler specific bronchoprovocation challenges: short interval administration of micronized freeze-dried allergen in children with bronchial asthma. III.

Two different methods of antigen bronchial challenge, with micronized freeze-dried extract of D. pteronyssinus administered as a powder by a spinhaler, were evaluated in 15 asthmatic children, who were skin test positive and RAST positive for house dust mite D. pteronyssinus. In one method, daily increasing dose method (DIDM), a single antigen challenge was performed every day successively. In the other method, cumulative dose method (CDM), the antigen doses were administered successively with 7-minute intervals. The tests were considered positive when there was a fall of FEV1 greater than or equal to 20% of the baseline value. The DIDM showed a greater incidence of isolated late bronchoconstrictions. The CDM revealed a great incidence of biphasic reactions (early and late) and of laryngeal spasm. Two patients showed discordant results (positive with one method and negative with the other) suggesting problems related to intrasubject reproducibility.

Adolescent↗
PubMed1987

Nebulised sodium cromoglycate and verapamil in methacholine induced asthma.

Fifteen children with asthma underwent challenges with methacholine on separate days after double blind administration by nebuliser of either verapamil (5 mg), cromoglycate (20 mg), or saline (placebo). The provocation doses that produced a 20% fall in forced expiratory volume in one second (PD20) were analysed. There was variation in the protective effects of verapamil and cromoglycate among the patients. Although cromoglycate produced an increase in PD20 in 53% of the children tested, the protection was not significant when compared with the placebo. Verapamil was partially protective, however, in 80% of children and achieved significantly better results than the placebo. We suggest that this is likely to be due to a direct effect on bronchial smooth muscle.

Adolescent↗
PubMed1987

Salbutamol and ipratropium bromide solution in the treatment of bronchospasm in asthmatic children.

The effects of the beta 2-adrenergic agonist salbutamol (0.02 mL/kg of a 0.5% solution) and the cholinergic antagonist ipratropium bromide (2 mL of a 0.025% solution), administered alone or in combination at different doses, were evaluated in 48 asthmatic children using a single-dose, double-blind, crossover design. Spirometric measurements were taken before and 10, 30, 60, 120, 180, 240, 300, and 360 minutes after administration of the drugs. All regimens produced significant bronchodilatation 10 to 30 minutes after administration. The improvement began to decline three to four hours after inhalation, particularly when ipratropium bromide was administered alone. The administration of the salbutamol plus ipratropium combination did not significantly improve pulmonary function values as compared to salbutamol alone. The effects of salbutamol and ipratropium bromide in half-dose or full-dose combinations were indistinguishable. No significant adverse effects on blood pressure or heart rate were observed.

Adolescent↗
PubMed1987

A new sustained-release theophylline suspension for asthmatic children: evaluation of serum theophylline concentrations.

Theophylline level variability obtained with standard slow-release theophylline tablets was compared to that obtained with a new sustained-release theophylline suspension in asthmatic children. The sustained-release preparations were administered every 12 hours and serum samples were collected after ten days of treatment during the steady-state period. In this crossover study, the sequence of the two regimens (slow-release tablets versus slow-release suspension) was selected at random. Both preparations of theophylline were administered at a mean dosage (+/- s.d.) of 19.3 +/- 1 mg/kg/day. The results of our study demonstrated that theophylline serum levels remain within the therapeutic range for both preparations, but there was a greater fluctuation with theophylline suspension compared to the tablets. The tolerability of the two drugs was satisfactory.

Adolescent↗