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Biomedical subjects

G Vallone

Publications and source records attributed to G Vallone.

At least 55 records · Page 3Linked to original sources
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↗
PubMed1986

Simplified spinhaler method for antigen-specific bronchoprovocation in children with bronchial asthma. I.

Specific bronchial challenge has been performed using a micronized, freeze-dried allergen extract of D. pteronyssinus administered as a powder at increasing concentrations (0, 50, 100, 200, 400, 600, 800, and 1,000 Allergenic Units) by a cromolyn spinhaler delivery system. The test was performed in ten asthmatic children with house mite D. pteronyssinus skin test and RAST positivity and in six non-allergic asthmatic children. A positive early reaction to bronchial challenge occurred in eight out of ten allergic children. A ninth child of this allergic group presented only the late reaction. Five patients of the control group (skin test and RAST negative for D. pteronyssinus had negative results while one child had a positive response both with early and late reactions. A significant increase in methacholine sensitivity was observed in the allergic group the day following the specific challenge. The modified spinhaler procedure (Hypoinhal, Lofarma) used for specific bronchial challenge showed a good correlation with skin test and RAST positivity in patients as well as in the control population. The method provides advantages of simplicity, ease of performance and cost effectiveness.

Administration, Intranasal↗
PubMed1986

Comparative study of two methods for spinhaler-specific bronchoprovocation challenges. II.

Two different methods of performing specific bronchial challenge using a micronized freeze-dried extract of D. pteronyssinus administered as a powder by a spinhaler have been evaluated in 11 children with chronic asthma and skin test RAST positive for house dust mite D. pteronyssinus. In the first method, "Cumulative Dose Method" (CDM), the test doses of antigen [0, 50, 100, 200, 400, 600, 800, and 1,000 Allergenic Units (A.U.)] were successively administered in 30-minute intervals. With the other method, "Daily Increasing Dose Method" (DIDM), a single antigen challenge (only one cup) was performed every day successively. The tests were considered positive when FEV1 values dropped below 20% of the value obtained immediately before the inhalation of the antigen. The early FEV1 fall was 36.6% +/- 10.8% with CDM and 29.1% +/- 11.5% with DIDM. There was a mean late fall of FEV1 52% +/- 17% and 35.3% +/- 12.2%, respectively, after a mean antigen administration of 270 +/- 149 A.U. with CDM and of 290 +/- 202 A.U. with DIDM. An increase in non-specific bronchial reactivity was observed after specific challenge performed with both methods. The CDM offers the advantage of obtaining information more quickly. The DIDM offers the advantage of administering a lower daily dose of antigen. Our results indicate that a modification of CDM with a shorter interval of administration may further improve this method of antigen administration.

Antigens↗
PubMed1985

Intrarectal ultrasound and computed tomography in the pre- and postoperative assessment of patients with rectal cancer.

The ability of intrarectal ultrasound to recognize the local extent of disease was investigated in 23 patients with histologically proven adenocarcinoma of the lower two-thirds of the rectum before operation. Two probes, 12 cm long, working at a frequency of 3.5 and 7.5 MHz, were used. The results were compared with those of pre-operative computed tomography (CT) and with the pathological report of the resected specimens. Sonography correctly staged 20 of 23 tumours with two false negatives and one false positive, while CT correctly staged 19 of 23 tumours with two false negatives and two false positives. The results of ultrasound were found to be as accurate as those of CT; the low cost and simple use of ultrasound makes it preferable in the pre-operative assessment of the depth of invasion of rectal cancer. In addition, intrarectal ultrasound was routinely performed in 42 patients, operated on for rectal cancer by means of sphincter-saving procedures, at variable intervals in the first 2 years postoperatively. Eight local recurrences were recognized and confirmed by CT. Based on the low cost, reliability and simple use, intrarectal ultrasound is proposed as first examination for local recurrence detection in the follow-up of patients with low anterior resection for rectal cancer.

Adenocarcinoma↗