Search PubMed⌕ Search

Biomedical subjects

F Zacchello

Publications and source records attributed to F Zacchello.

At least 19 recordsLinked to original sources
PubMed2001

Endogenous surfactant turnover in preterm infants with respiratory distress syndrome studied with stable isotope lipids.

We studied surfactant kinetics on Day 1 of life in 11 preterm infants on mechanical ventilation by infusing stable isotope labeled palmitic (PA) and linoleic acid (LLA). Six infants received exogenous surfactant for the treatment of respiratory distress syndrome (RDS) and five did not meet treatment criteria because of minimal or no disease. The isotopic enrichment of plasma free PA and LLA and of surfactant phosphatidylcholine PA (PC-PA) and LLA (PC-LLA) from tracheal aspirates was measured by mass spectrometry. Significant isotopic enrichment could be measured in PC-PA and PC-LLA from all patients. The fractional synthesis rate (FSR) of PC-LLA was higher than that of PC-PA (22.7 +/- 15.9 versus 12.1 +/- 7.7% per day, p = 0.018). Half-life (HL) of PC-PA was longer than that of PC-LLA (94.7 +/- 18.8 versus 46.6 +/- 32.6 h, p = 0.028). Patients who received exogenous surfactant had longer secretion times (ST) and delayed peak times (PK) but FSR and HL were unaffected. We concluded that: (1) surfactant kinetics can be measured in preterm infants with stable isotope labeled lipids; (2) surfactant FSR and HL calculated with PA and LLA gave different results; (3) patients treated with exogenous surfactant had similar FSRs compared with the nontreated subjects but had longer ST and delayed PK; (4) FSR from plasma free fatty acids (present study) was higher than that from plasma glucose in our previous work (Bunt JEH, Zimmermann LJI, Wattimena D, van Beek R, Sauer PJJ, Carnielli VP. Am J Respir Crit Care Med 1998;157:810-814) in a comparable population of preterm infants with RDS.

Humans↗
PubMed2000

Metabolic and respiratory effects of theophylline in the preterm infant.

BACKGROUND: Methylxanthines are often administered to preterm infants for the treatment of apnoea. AIMS: To study the effects of theophylline on energy metabolism, physical activity, and lung mechanics in preterm infants. METHODS: Indirect calorimetry was performed for six hours before and after administration of a bolus of theophylline (5 mg/kg) in 18 preterm infants while physical activity was recorded with a video camera. Lung mechanics measurements were performed at baseline and 12 and 24 hours after theophylline treatment. RESULTS: Theophylline increased mean (SEM) energy expenditure by 15 (5) kJ/kg/day and augmented carbohydrate utilisation from 6.8 to 8.0 g/kg/day, but fat oxidation was unchanged. After theophylline treatment, preterm infants had faster respiration, lower transcutaneous CO2, and improved static respiratory compliance without increased physical activity. CONCLUSIONS: A bolus of 5 mg/kg theophylline increased energy expenditure independently of physical activity, increased carbohydrate utilisation, and improved respiratory compliance. The increased energy expenditure could be detrimental to the growth of the preterm infant.

Aminophylline↗
PubMed2000

Exhaled nitric oxide and exercise-induced bronchoconstriction in asthmatic children.

It is known that exhaled nitric oxide (ENO) is increased in asthmatic individuals, probably as an expression of airway inflammation, but no studies have been reported of ENO and exercise-induced bronchoconstriction (EIB). We assessed the effect of a treadmill exercise challenge on ENO concentration in 24 asthmatic children aged 11.2 +/- 0.4 yr (mean +/- SEM). According to the presence or absence of EIB, the children were divided into an EIB group (n = 10) and a non-EIB group (n = 14). ENO was measured with a single-breath reservoir technique. FEV(1), ENO, and heart rate were measured at baseline and 1, 6, 12, and 18 min after the end of exercise. We also measured ENO in 18 healthy control children aged 10.8 +/- 0.6 yr, of whom nine underwent an exercise challenge identical to that of the asthmatic children. After the exercise test, the mean decrease in FEV(1) was 34% in the EIB group and 5% in the non-EIB group. The EIB group had higher baseline ENO values (12.3 +/- 1.6 ppb) than the healthy children (6.1 +/- 0.2 ppb) (p < 0.01). The time course of ENO was similar in the EIB, non-EIB, and control groups, with no significant changes after exercise (p = NS). In the overall group of asthmatic children there was a significant correlation (r = 0.61, p < 0.01) between baseline (preexercise) ENO and magnitude of the maximal decrease in FEV(1) after exercise. In conclusion, our study shows that ENO levels do not change during acute airway obstruction induced by exercise challenge in asthmatic children. In addition, baseline ENO values correlate with the magnitude of postexercise bronchoconstriction, suggesting that NO may be a predictor of airway hyperresponsiveness to exercise.

Adolescent↗
PubMed2000

Exogenous surfactant kinetics in infant respiratory distress syndrome: A novel method with stable isotopes.

Little is known about surfactant metabolism in newborn infants, since radioactive isotopes cannot be used in humans. We describe here a new method for studying exogenous surfactant pharmacokinetics in vivo. We measured surfactant half-life, pool size, and turnover time in eight preterm infants (gestational age: 30 +/- 2 wk; birth weight: 1,416 +/- 202 g) who were mechanically ventilated because of infant respiratory distress syndrome. We administered two doses of 100 mg/kg each of a natural porcine surfactant with (13)C-labeled dipalmitoylphosphatidylcholine as a tracer. The (13)C enrichment of surfactant disaturated phosphatidylcholine (DSPC) was measured in serial tracheal aspirates by gas chromatography-mass spectrometry. The DSPC half-life was 34.2 +/- 9.4 h (mean +/- SD; range: 21.8 to 45.9 h). The apparent DSPC pool sizes were 5.8 +/- 6.1 mg/kg (range: 0.1 to 17.0 mg/kg) and 17.3 +/- 13.6 mg/kg (range: 3.3 to 41.0 mg/kg) at the time of the first and second surfactant doses, respectively. We present a novel and safe method that allows the tracing of exogenous surfactant phosphatidylcholine, the major lipid component of pulmonary surfactant, in infants who receive exogenous surfactant. This method could be a valuable tool for studying: (1) therapies that enhance lung/surfactant maturation; (2) the dosing and timing of surfactant therapy in different lung diseases; and (3) the comparison of different surfactant preparations.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed2000

A simple flow-driven method for online measurement of exhaled NO starting at the age of 4 to 5 years.

NO is increased in exhaled air of asthmatic patients, and may be used as a marker of airway inflammation. The online method is a standardized technique for measuring exhaled nitric oxide (ENO). However, this method has proven difficult for some children, who may have trouble maintaining a constant expiratory flow. The aim of this study was to validate a modified technique for online ENO measurement that utilizes a flow regulator to overcome the patient problem of having to actively maintain a constant expiratory flow. We measured ENO levels with two methods in 105 asthmatic and 10 healthy subjects, comparing the standardized (ST) single-breath method with a modified single-breath, flow-driven (FD) method. With the ST method and visual monitoring, the subjects inhaled NO-free air to TLC, and exhaled with a target flow of 50 ml/s. With the FD method, the subjects exhaled from TLC and flow was kept constant (50 ml/s) by the operator, using a flow regulator. The subjects were divided into two groups, one consisting of children aged 4 to 8 yr (n = 74) and the other of children aged 9 to 16 yr (n = 41). In the group aged 4 to 8 yr, 38 children (51%) were unable to perform the ST method, whereas only five children (7%) failed to perform the FD technique. In the group aged 9 to 16 yr, only four children (10%) were unable to perform the ST maneuver, and all successfully performed the FD maneuver. The mean concentrations of ENO in the 73 children who performed both types of maneuver were similar (36.1 +/- 3.4 [mean +/- SEM] ppb with the ST method and 33.8 +/- 3.3 ppb with the FD technique, p = NS) and were highly correlated with one another (r = 0.99, p < 0.0001). ENO values were significantly higher in steroid-naive than in steroid-treated asthmatic children. In conclusion, we describe a modified online method for measuring ENO that is simple, does not require active cooperation to maintain a constant expiratory flow, and can be easily performed by children from 4 to 5 yr of age onward.

Adolescent↗
PubMed2000

Functional approach to infants and young children with noisy breathing: validation of pneumotachography by blinded comparison with bronchoscopy.

Flow-volume loop evaluation yields considerable diagnostic information about adult patients with upper airway obstruction. No conclusive data support the reliability of this method in young children with noisy breathing. We used analysis of flow-volume loops at tidal breathing (TB-FV) as a first diagnostic approach to young children presenting with persistent noisy breathing (chronic stridor and/or wheezing). Flexible fiberoptic bronchoscopy was performed to establish a conclusive diagnosis and was used to verify the accuracy of the preliminary functional localization of the airway obstruction causing noisy breathing. The physician conducting pneumotachography was blinded to the bronchoscopic findings in the study, and the investigators conducting bronchoscopy were blinded to the pneumotachographic findings. Through a 6-yr period, 113 consecutive young children (ranging in age from 15 to 48 mo) with noisy breathing were enrolled in the study. Three morphologically abnormal TB-FV patterns, as compared with the normal round-shaped TB-FV loops obtained with 15 healthy children, were identified in 110 patients. A TB-FV pattern of inspiratory fluttering was found in 26 subjects and in the first 3 yr of the study was always associated with an endoscopic diagnosis of isolated laryngomalacia. Subsequently, this pattern was used to diagnose isolated laryngomalacia in 18 other infants, in whom endoscopy was avoided. Of infants with endoscopic evidence of airway obstruction ranging from the glottis to the mainstem bronchi (49 subjects), all but three showed a TB-FV loop pattern characterized by expiratory-limb flattening. A concave expiratory loop, with early expiratory peak flow and low flow at low volume, was invariably associated with peripheral bronchoconstriction, without endoscopic evidence of anatomic abnormalities (20 cases). In conclusion, TB- FV loop analysis is a noninvasive, accurate method of establishing the site of airway obstruction in young children with recurrent stridor and/or wheezing. Clinical use of this method may provide interesting pathophysiologic information and may be useful in addressing the diagnostic management of such children.

Airway Obstruction↗
PubMed1999

Polyethylenimine shows properties of interest for cystic fibrosis gene therapy.

Before being considered for a cystic fibrosis (CF) gene therapy trial, any gene delivery agent must be able to show that it produces low levels of toxicity as well as being able to protect the DNA from nuclease degradation. Here we show that complexes of linear polyethylenimine (L-PEI) and DNA can repeatedly be administered to animals (up to 21 consecutive days) without eliciting an immune response against PEI/DNA particles or inducing toxic side effects due to accumulation of PEI in the lungs. However, the host response to the exogenous protein resulted in some decrease of expression. PEI-mediated transfection was unaffected by treatment of the complexes with DNase (frequently used to reduce the viscosity of lung secretions in CF patients). Taken together, these properties make L-PEI a valuable vector for gene therapy of CF.

Cystic Fibrosis↗
PubMed1999

Identification of a D579G homozygote cystic fibrosis patient with pancreatic sufficiency and minor lung involvement. Mutations in brief no. 221. Online.

Here we describe the identification of an italian patient homozygote for the D579G mutation affected by a mild form of Cystic Fibrosis with pancreatic sufficiency, minor lung involvement and marked viscosity of the cervical mucous. The D579G mutation causes an A1868G transition, a substitution of an aspartic acid to a glycine residue, generating an important amino acid change (charged to hydrophobic) in the nucleotide-binding domain (NBD). The mutation was first described by Brancolini et al. (1995) on two pancreatic sufficient CF patients, compound heterozygotes for delta508F. Patients were from Southern Italy (Puglia) as the D579G homozygote one, who is a 30 years old woman from Taranto (Puglia), daughter of second cousins born in Bari (Puglia). The identification of a homozygote D579G patient might confirm that this mutation does correlate with pancreatic sufficiency and a mild pulmonary phenotype.

Adult↗
PubMed1999

Reference values of exhaled nitric oxide for healthy children 6-15 years old.

Nitric oxide (NO) can be detected in human exhaled air, and its endogenous production is increased in patients with asthma. It may provide a noninvasive means for measuring airway inflammation. The aim of this study was to establish reference values for exhaled NO concentrations in a large number of healthy school-age children. We measured exhaled NO levels in 159 white healthy children (88 girls, 71 boys, age range 6-15 years) recruited from two public schools of Padua, Italy. Exhaled NO levels in exhaled gas were measured by a tidal breathing method with a chemiluminescence analyzer, and NO steady-state levels were recorded. Nasal NO levels were measured by direct sampling from the nose during mouth breathing. The mean concentration of endogenous NO in orally exhaled gas was 8.7 parts per billion (ppb) (95% confidence interval (C.I.), 8.1-9.2 ppb) and sampled data followed a log-normal distribution (Kolmogorov-Smirnov d = 0.77, P > 0.2). No difference was found between boys (mean value, 8.4 ppb; 95% C.I., 7.3-9.4 ppb) and girls (mean value, 8.9 ppb; 95% C.I., 7.9-9.9 ppb). No significant correlation was found between age, height, or spirometric data and exhaled NO levels (r < 0.2). The mean value of nasal NO concentrations was 216 ppb (95% C.I., 204-228 ppb). There was no correlation between exhaled and nasal NO values (r = 0.16, P = ns). In conclusion, this study establishes a reference range for exhaled NO values measured by a tidal breathing method in children between age 6-15 years. The observed levels are independent of age, gender, and lung function, and can be used to monitor airway inflammation in asthmatic children.

Adolescent↗
PubMed1999

Clinical and biochemical approach to the neonate with a suspected inborn error of amino acid and organic acid metabolism.

Disorders of amino acid and organic acid metabolism collectively represent a group of over 70 inherited diseases that are most frequently encountered in the neonatal period. A neonate with clinical symptoms caused by one of these disorders is a real clinical emergency, a situation complicated by the similarities to the manifestations seen in sepsis or asphyxia. Delay of diagnosis and proper treatment often results in severe morbidity and high mortality. The vast majority of these patients are likely to be transferred to a neonatal intensive care unit, suggesting that amino acid and organic acid biochemical screenings should be performed in these newborns routinely at admission. The analysis of amino acids and acylcarnitines in blood spots by tandem mass spectrometry has the potential to significantly improve the morbidity and mortality rates of metabolic disorders with neonatal presentation. In the case of disorders lacking an effective treatment, an early diagnosis could lead to proper genetic counseling of the parents and to the option of reliable prenatal diagnosis of future pregnancies. This review offers an updated summary of the clinical, biochemical, and therapeutic features of the aminoacidopathies and organic acidurias most likely to be encountered in neonatal clinical practice.

Amino Acid Metabolism, Inborn Errors↗
PubMed1999

Effect of cagA status on the sensitivity of enzyme immunoassay in diagnosing Helicobacter pylori-infected children.

BACKGROUND: The aims of our study were twofold. First, we sought to evaluate in symptomatic children the influence of the Helicobacter pylori genotype on gastritis, abdominal pain, and circulating anti-H. pylori IgG antibodies (anti-H. pylori IgG) or pepsinogen A (PGA) and C (PGC). Additionally, we sought to assess anti-H. pylori IgG, PGA, and PGC patterns in a large cohort (N = 921) of asymptomatic children. MATERIALS AND METHODS: In 183 symptomatic children, H. pylori infection and the presence of gastritis were evaluated by histology. In a subgroup of 20 H. pylori-positive children, the H. pylori genotype was evaluated also by polymerase chain reaction. Nine hundred and twenty-one asymptomatic children, aged 11 to 14 years, were studied by anti-H. pylori IgG, PGA, and PGC serum determination. RESULTS: The infection was found in 33 of 183 symptomatic children; among the 20 H. pylori-positive children for which the H. pylori genotype was available, cagA was present or absent in equal percentages. H. pylori infection was associated with more severe gastritis and higher serum levels of anti-H. pylori IgG and PGC but not with abdominal pain. In infected children, higher levels of anti-H. pylori IgG and the presence of abdominal pain were associated with infections caused by cagA-positive strains. In the cohort of 921 asymptomatic children, raised levels of anti-H. pylori IgG, PGA, and PGC were found in approximately 5% of the cases. CONCLUSIONS: Infection with cagA-positive H. pylori strains can be associated with increased frequency of reported abdominal pain and higher circulating levels of anti-H. pylori IgG. The serological assessment of H. pylori IgG using H. pylori antigens containing significant amounts of cagA protein may, therefore, underestimate the true prevalence of infection.

Abdominal Pain↗
PubMed1999

Effect of natural grass pollen exposure on exhaled nitric oxide in asthmatic children.

Exhaled nitiric oxide (NO) is increased in exhaled breath of asthmatic patients. The aim of this study was to investigate the longitudinal changes of exhaled NO outside and during the pollen season in pollen-allergic asthmatic children. Twenty-one children (age 6 to 16 yr), with a seasonal allergic asthma sensitive to grass pollen, underwent measurements of exhaled NO and pulmonary function before (March), during (May), and after (November) the pollen season. Exhaled NO was measured by a tidal breathing method with a chemiluminescence analyzer and NO steady-state levels were recorded. The timing of the measurements during the pollen season was based on the atmospheric pollen count. Exhaled NO values of asthmatic children were compared with those of 21 sex- and age-matched healthy children. Pulmonary function and symptoms of asthma were also evaluated at each visit. The mean value of exhaled NO before the grass season was 12.7 +/- 5.1 ppb (mean +/- SD), significantly higher when compared with controls (7.8 +/- 2.7 ppb, p < 0.001). In the pollen season there was a significant (p < 0.001) twofold increase in exhaled NO (21.4 +/- 7.6 ppb) that, after the season, returned to values similar (12.8 +/- 5.8 ppb, p = NS) to those found before the season. There were no significant changes in FEV1 before and during the season (98.6% predicted versus 101% predicted, p = NS). We conclude that natural allergen exposure is related to an increase of exhaled NO in asthmatic grass pollen-allergic children even in absence of significant changes in airways function. We speculate that measurement of exhaled NO could be a sensitive noninvasive marker of asthma disease activity.

Adolescent↗
PubMed1999

Exhaled nitric oxide concentrations during treatment of wheezing exacerbation in infants and young children.

While it is known that exhaled nitric oxide (ENO) is increased in adults and school children with asthma exacerbation probably as an expression of disease activity, no studies have investigated whether this phenomenon also occurs in infants and young children with recurrent wheeze exacerbation. We measured ENO in 13 young children (mean age 20.2 mo) with recurrent wheeze (Group 1) during an acute episode and after 5 d of oral prednisone therapy. ENO was measured also in nine healthy control subjects (Group 2) (mean age 16.9 mo) and in six children with a first-time viral wheezy episode (Group 3) (mean age 11 mo). To measure ENO, infants inhaled NO-free air via a face mask from a reservoir and, through a nonrebreathing valve, exhaled in a collecting bag that was analyzed by chemiluminescence. To address the question of whether the levels of ENO collected in the bag are a reflection of the pulmonary airway, ENO determinations were performed in two healthy infants before and after tracheal intubation for elective surgery. During the acute episode of wheezing the mean (+/- SEM) value of ENO in children with recurrent wheeze (Group 1) was 14.1 +/- 1.8 ppb, almost threefold higher than in healthy control subjects (5.6 +/- 0.5 ppb, p < 0.001). After steroid therapy we found a mean fall of 52% in ENO (5.9 +/- 0.7 ppb, p < 0.01) compared with baseline values. ENO values measured before and after intubation in two infants were 6 ppb and 5 ppb in one child and 7 ppb and 6 ppb in the other one. The mean value of ENO of children with first-time wheeze (Group 3) was 8.3 +/- 1.3 ppb, significantly lower (p < 0.05) than the value of children with recurrent wheeze (Group 1). In conclusion, we describe a method to measure ENO in young children and show that infants with recurrent wheeze have elevated levels of ENO during exacerbation that rapidly decrease after steroid therapy. This suggests that, in these children, airway inflammation could be present at a very early stage.

Acute Disease↗
PubMed1999

Endogenous surfactant metabolism in critically ill infants measured with stable isotope labeled fatty acids.

Little is known about endogenous surfactant metabolism in infants, because radioactive isotopes used for this purpose in animals cannot be used in humans. We developed a novel and safe method to measure the endogenous surfactant kinetics in vivo in humans by using stable isotope labeled fatty acids. We infused albumin-bound [U-13C]palmitic acid (PA) and [U-13C]linoleic acid (LLA) for 24 h in eight critically ill infants (mean+/-SD: weight: 3.7+/-1.3 kg: age: 51.3+/-61.6 d) who required mechanical ventilation. The 13C enrichment of PA and LLA in surfactant phosphatidylcholine (PC), obtained from tracheal aspirates, was measured by gas chromatography combustion interface-isotope ratio mass spectrometry. We measured a significant incorporation of both 13C-PA and 13C-LLA into surfactant PC. PC-PA and PC-LLA became enriched after 8.7+/-4.9 h (range: 3.4-17.3) and 10.0+/-7.2 h (range: 3.0-22.4), respectively; the times at maximum enrichment were 49.2+/-8.9 and 45.6+/-19.3 h, respectively. The fractional synthesis rate of surfactant PC-PA ranged from 0.4 to 3.4% per h, whereas the fractional synthesis rate of PC-LLA ranged from 0.5 to 3.8% per h. The surfactant PC-PA and PC-LLA half-lives ranged from 16.8 to 177.7 and 23.8 to 144.4 h, respectively. This method provides new data on surfactant metabolism in infants requiring mechanical ventilation. We found that synthesis of surfactant from plasma PA and LLA is a slow process and that there were marked differences in PC kinetics among infants. This variability could be related to differences in lung disease and could affect the clinical course of the respiratory failure.

Carbon Isotopes↗
PubMed1999

Cx26 deafness: mutation analysis and clinical variability.

Mutations in the gap junction protein connexin 26 (Cx26) gene (GJB2) seem to account for many cases of congenital sensorineural hearing impairment, the reported prevalence being 34-50% in autosomal recessive cases and 10-37% in sporadic cases. The hearing impairment in these patients has been described as severe or profound. We have studied 53 unrelated subjects with congenital non-syndromic sensorineural hearing impairment in order to evaluate the prevalence and type of Cx26 mutations and establish better genotype-phenotype correlation. Mutations in the Cx26 gene were found in 53% of the subjects tested, 35.3% of the autosomal recessive and 60% of the sporadic cases in our series. Three new mutations were identified. The hearing deficit varied from mild to profound even in 35delG homozygotes within the same family. No evidence of progression of the impairment was found. Alterations of the Cx26 gene account for a large proportion of cases of congenital non-syndromic sensorineural deafness, so it seems appropriate to extend the molecular analysis even to subjects with mild or moderate prelingual hearing impairment of unknown cause.

Adolescent↗
PubMed1998

Effect of atmospheric nitric oxide (NO) on measurements of exhaled NO in asthmatic children.

The measurement of exhaled nitric oxide concentrations [NO] may provide a simple, noninvasive means for measuring airway inflammation. However, several measurement conditions may influence exhaled NO levels, and ambient NO may be one of these. We measured exhaled NO levels in 47 stable asthmatic children age 5 to 17 years and in 47 healthy children, gender and age matched. Exhaled [NO] in expired air was measured by a tidal breathing method with a chemiluminescence analyzer, sampling at the expiratory side of the mouthpiece. NO steady-state levels were recorded. In order to keep the soft palate closed and avoid nasal contamination, the breathing circuit had a restrictor providing an expiratory pressure of 3-4 cm H2O at the mouthpiece. To evaluate the effect of [NO] in ambient air, measurements were randomly performed by breathing ambient air or NO-free air from a closed circuit. Breathing NO-free air, exhaled [NO] in asthmatics (mean +/- SEM) was 23.7 +/- 1.4 ppb, significantly higher (P < 0.001) than in healthy controls (8.7 +/- 0.4 ppb). Exhaled NO concentrations measured during ambient air breathing were higher (49 +/- 4.6 ppb, P < 0.001) than when breathing NO-free air (23.7 +/- 1.4 ppb) and were significantly correlated (r = 0.89, P < 0.001) with atmospheric concentrations of NO (range 3-430 ppb). These findings show that 1) exhaled [NO] values of asthmatic children are significantly higher than in healthy controls, and 2) atmospheric NO levels critically influence the measurement of exhaled [NO]. Therefore, using a tidal breathing method the inhalation of NO-free air during the test is recommended.

Adolescent↗
PubMed1998

Effect of topical steroids on nasal nitric oxide production in children with perennial allergic rhinitis: a pilot study.

It has been hypothesized that concentrations of exhaled nitric oxide (NO) may be related to the extent of cytokine-mediated airway inflammation. Recent findings indicate the nasal airways as an important site of NO production. Our objective was to evaluate whether children with allergic rhinitis show different nasal NO levels when compared with normal healthy subjects and the effect of topical steroids and anti-histamine therapy. We have measured the concentration of NO drawn from the nose of 21 children (5-17 years old) affected by perennial allergic rhinitis (house dust mite) out of therapy for at least 3 weeks. Thirteen children were then treated with nasal beclomethasone dipropionate (BDP) (400 micrograms daily) and eight subjects with nasal anti-histamine levocabastine (200 micrograms daily). Measurements were performed before and after 10 days of treatment. As a control group we evaluated 21 healthy children aged 5-15 years. To measure NO we used a chemiluminescence analyser. Before treatment the whole group of children with allergic rhinitis showed a mean (+/- SEM) nasal NO concentration of 267 +/- 18 ppb, significantly higher (P < 0.01) than the control group (186 +/- 15 ppb). The group of children treated with BDP showed, after 10 days of therapy, a significant (P < 0.05) decrease of nasal NO concentration (271 +/- 21 ppb vs. 212 +/- 20 ppb). Indeed, in the group treated with levocabastine, nasal NO concentrations did not present a significant difference (P not significant) compared with baseline (261 +/- 33 ppb and 252 +/- 31 ppb, respectively). These data suggest that (1) children with allergic rhinitis have higher levels of nasal NO than non-atopic controls and (2) intranasal steroid therapy significantly reduces nasal NO production in children with allergic rhinitis. We speculate that the allergic inflammatory response may influence the nasal NO levels and that NO measurements may be a useful marker of nasal inflammation.

Adolescent↗