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Fifteen healthy volunteers took part in a study to investigate the effect of food on the bioavailability of a slow‐release formulation of theophylline. Serum theophylline levels were measured every two hours for ten hours after a single oral dose of 500 mg of theophylline. Serum levels were significantly higher after the dose was taken on an empty stomach; however, serum levels were significantly higher 10 hours later when the dose was taken after a standard meal. Despite these differences, eating had no overall effect on theophylline bioavailability. Two analytic methods for measuring serum levels of theophylline were compared, and it was found that fluorometry could measure lower levels and was therefore more precise than an enzyme immunoassay method, which is probably due to the complete automation and reduced interference of bilirubin and hemoglobin.

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 (1 3)%, 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.

Samples of the respiratory mucosa of children with recurrent respiratory infections suspected of having primary ciliary dyskinesia are routinely fixed with glutaraldehyde before ultrastructural examination. This standard technique, however, may not be optimal for visualizing ciliary components or for preserving several cellular and extracellular structures during dehydration and embedding procedures. In this study, brushes of nasal (28 samples) and/or tracheal (9 samples) mucosa from 32 children with recurrent respiratory tract infections were examined. Twenty-nine samples were fixed with glutaraldehyde supplemented with tannic acid to determine if the ultrastructural analysis of respiratory epithelium and bronchial secretions could be improved. Eight samples were conventionally fixed with glutaraldehyde alone. Lesions of the cellular membrane and damaged cells were easily visualized using tannic acid supplemented fixation. Internal ciliary structures including individual microtubules and dynein arms were also more clearly observed. In addition, the internal structure of microvilli of the respiratory epithelium could be studied and the presence of phospholipid-rich surfactant-like material within nasal and tracheal secretions were visualized after tannic acid supplemented fixation. We suggest that addition of tannic acid during fixation is useful for accurate ultrastructural evaluation of respiratory mucosa in both clinical and experimental situations.

To investigate the role of echo-Doppler flowmetry in evaluating patients with cystic fibrosis and portal hypertension at risk of esophageal varices, we studied 26 subjects divided in 3 groups: 9 with portal hypertension and esophageal varices, 8 with chronic liver disease without varices, and 9 without chronic liver disease. Spleen size, diameter, blood velocity, and flow rate of portal, splenic, and superior mesenteric veins were recorded. In patients without chronic liver disease Doppler measurements were repeated on 2 different days to assess intraobserver variability. Significant differences among the three groups were found for mean values of spleen size and diameters of portal, splenic, and superior mesenteric veins. Nevertheless, a considerable overlapping of individual data was observed. No differences were observed in mean hemodynamic measurements, except for blood velocity in portal vein and flow rate in splenic vein. The intraobserver variability for repeated Doppler measurements was clinically unacceptable for most of the variables studied. Echo-Doppler assessment of splanchnic flow seems to be an unreliable tool in the management of cystic fibrosis patients with portal hypertension at risk of esophageal varices.

The aim of this study was to evaluate the reliability of serum IgA anti-gliadin antibodies (IgA-AGA) in the monitoring of gluten challenge and in the prediction of mucosal relapse in children with celiac disease (CD) in order to reduce the challenging procedure to a minimum. Serial evaluations of serum IgA-AGA titers and 1-h blood xylose levels were performed in 17 children with celiac disease during gluten challenge. Jejunal biopsy was generally done after two consecutive measurements of positive IgA-AGA. The morphological appearance of the mucosa and intraepithelial lymphocyte infiltration were also evaluated. A serum positive for IgA-AGA was observed in 16 of 17 patients between the 15th and 35th day of challenge. The challenge was concluded in all children after 20–45 days from the introduction of a glutencontaining diet after histological confirmation of CD. Plasma xylose test was less reliable in this respect. We conclude that IgA-AGA measurement by gluten challenge is likely to simplify and allow earlier diagnostic confirmation of celiac disease in children, without intestinal biopsy.

The aim of this study was to evaluate the reliability of serum IgA anti-gliadin antibodies (IgA-AGA) in the monitoring of gluten challenge and in the prediction of mucosal relapse in children with celiac disease (CD) in order to reduce the challenging procedure to a minimum. Serial evaluations of serum IgA-AGA titers and 1-h blood xylose levels were performed in 17 children with celiac disease during gluten challenge. Jejunal biopsy was generally done after two consecutive measurements of positive IgA-AGA. The morphological appearance of the mucosa and intraepithelial lymphocyte infiltration were also evaluated. A serum positive for IgA-AGA was observed in 16 of 17 patients between the 15th and 35th day of challenge. The challenge was concluded in all children after 20–45 days from the introduction of a glutencontaining diet after histological confirmation of CD. Plasma xylose test was less reliable in this respect. We conclude that IgA-AGA measurement by gluten challenge is likely to simplify and allow earlier diagnostic confirmation of celiac disease in children, without intestinal biopsy.

Plasma fibronectin (FN) concentrations were measured by an immunonephelometric method in cord blood from 76 healthy newborns (45 full term and 31 preterm), in 181 healthy children, from 1 month–15 years old, divided by age into seven groups and in 81 control adults. FN levels in newborns were 35% of those of adults. There was no difference between plasma FN in term and preterm (gestational age>30 weeks) infants. Preterm newborns below the gestational age of 30 weeks showed particularly low FN levels. No clear correlation was seen with birth weight. In the child population, a strong increase in FN values was noted in the first 6 months of life, rising to 65% of the normal adult values. No further increase occurred until puberty.

Although basic mechanisms of bronchial hyper-responsiveness (BHR) are still incompletely understood, inflammation of airways is likely to play a fundamental role in modulating BHR in patients with asthma. The involvement of several inflammatory cells (eosinophils, mast cells, lymphocytes, neutrophils, macrophages and platelets) and of bioactive mediators secreted by these cells in the pathogenesis of asthma is well documented. Sodium cromoglycate and nedocromil sodium are two pharmacological agents which have anti-allergic and anti-inflammatory properties. Their clinical effectiveness in mild to moderate asthma, and the capacity to reduce BHR under different natural and experimental conditions, make them valuable drugs for maintenance therapy in patients with asthma.