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Biomedical subjects

G Gherson

Publications and source records attributed to G Gherson.

At least 19 recordsLinked to original sources
PubMed2002

Actions other than smooth muscle relaxation may play a role in the protective effects of formoterol on the allergen-induced late asthmatic reaction.

Long-acting beta(2)-adrenoceptor agonists attenuate the allergen-induced late asthmatic reaction. We evaluated whether other mechanisms in addition to airway smooth muscle relaxation may be implicated in this protective effect. The effects of formoterol (Foradil Aerolizer(TM), 24 microg dry powder) on the late asthmatic reaction were assessed by a randomised crossover factorial study in 24 patients with asthma. Four challenge/treatment combinations were tested: (A) saline/placebo, (B) saline/formoterol, (C) allergen/placebo, (D) allergen/formoterol. Formoterol and placebo were administered double blind after the last inhalation of the allergen or saline. FEV(1) was measured up to 32 h. The bronchodilator effect of formoterol was estimated as (B-A) and the overall protective effect as (D-C). The effect not due to bronchodilation was estimated as [(D-C)-(B-A)]/2. The bronchodilator effect of formoterol was statistically significant up to 5h (all P< or =0.015). Formoterol significantly attenuated the late asthmatic reaction between 3 and 32 h after allergen inhalation (all P< or =0.0012). The difference between this protective effect and the bronchodilator effect was statistically significant at 5 h and between 7 and 28 h after allergen inhalation (all P< or =0.035). Our results suggest that functional antagonism may not be the sole mechanism by which formoterol attenuates the allergen-induced late asthmatic reaction.

Adolescent↗
PubMed1998

Prevalence of sensitization to Alternaria in allergic patients in Italy.

BACKGROUND: The actual prevalence of sensitization to Alternaria is not known, partly due to the unreliability of diagnostic extracts. OBJECTIVE: To assess skin positivity to extracts of Alternaria in a wide population of Italian patients suffering from respiratory symptoms using a biologically standardized extract. METHODS: A total of 2942 patients were skin prick tested with Alternaria, and a panel of common inhalant allergens. Blood samples for specific IgE quantitation were taken both from patients positive and from patients negative (control group) to Alternaria extract. RESULTS: Three hundred six patients (10.4%, ranging from 1.8% in Turin to 29.3% in Cagliari) were positive to Alternaria; 37 were sensitized to only this mold, while the remaining 269 were sensitized to at least one other allergen. Of the Alternaria-positive patients, 79.7% suffered from rhinitis and 53.3% from asthma, either alone or associated with other symptoms. CONCLUSIONS: We suggest that, at least in Italy and in countries with similar climatic and environmental situations, standardized Alternaria extract should be included in the panel commonly used in investigating the allergen responsible in patients suffering from respiratory allergy.

Adolescent↗
PubMed1997

Comparison between peak expiratory flow and forced expiratory volume in one second (FEV1) during bronchoconstriction induced by different stimuli.

To evaluate the sensitivity of peak expiratory flow (PEF), obtained by portable peak flow meter, in detecting mild changes in airway caliber as assessed by forced expiratory volume in 1 sec (FEV1), we studied 184 subjects who underwent different bronchial challenge tests for suspected bronchial asthma. We measured FEV1 and PEF during bronchoconstriction induced by different stimuli: allergen, methacholine, toluene diisocyanate vapors, exercise, or distilled water inhalation; a total of 186 tests were examined. Before and at different times after challenge, FEV1 was measured, and immediately after, PEF was obtained by Mini-Wright or Assess Peak Flow Meter; each time FEV1 and PEF were taken as the best of three satisfactory tracings. The median FEV1 change from baseline value of all steps in the different challenge tests was 7.5% (range: 0-66%). The correlation coefficients between FEV1 and PEF percent changes in different challenge tests were low (Spearman's p: 0.27-0.69), with high scattering of the data. The concordance between classes of percent changes in FEV1 and PEF was also low (Cohen's weighted kappa: 0.28-0.42). In subjects with a FEV1 fall > 15% after challenge, the median PEF change after bronchoconstriction was lower than the corresponding FEV1 change [17% (0-52) vs. 27% (17-66)]. When different cutoff limits of PEF percent change were considered, the sensitivity of PEF to detect a significant change in FEV1 (15 or 20% change) during bronchoconstriction was low; specificity was in general higher than sensitivity. We conclude that PEF and FEV1 changes are poorly related during mild bronchoconstriction induced by different stimuli. The low sensitivity of PEF to detect mild changes in airway caliber may represent a limit in the use of PEF in the day-to-day monitoring of asthma.

Allergens↗
PubMed1996

Once daily intranasal fluticasone propionate (200 micrograms) reduces nasal symptoms and inflammation but also attenuates the increase in bronchial responsiveness during the pollen season in allergic rhinitis.

BACKGROUND: Fluticasone propionate aqueous nasal spray, a new topical corticosteroid, has been proved to be an effective treatment for seasonal allergic rhinitis. OBJECTIVES: We studied the effect of fluticasone propionate on nasal symptoms, circulating eosinophils, and nasal inflammation in patients with seasonal allergic rhinitis after high-load pollen exposure. Moreover, we examined its efficacy in preventing the increase in bronchial responsiveness to methacholine (PD20) during the pollen season. METHODS: We conducted a double-blind, placebo-controlled, parallel-group study in patients who had a history of allergic rhinitis in response to pollens of grass and Parietaria species and were living in northern Italy. After a run-in period of 2 weeks, 24 patients were treated with fluticasone propionate (200 micrograms, once daily), and 26 patients received matched placebo for 6 weeks, starting from the beginning of the pollen season. Assessment of efficacy was based on scores of daily nasal symptoms. Nasal lavage was performed at the end of the season, and differential cell count was expressed as percent of total cells. PD20 methacholine was measured at the beginning and end of the season and after the season had ended. RESULTS: Fluticasone propionate significantly reduced nasal obstruction, itching, and rhinorrhea. Eosinophils in blood (p < 0.01) and nasal lavage (p < 0.001) were also reduced. Moreover, fluticasone significantly attenuated the decrease in mean PD20 methacholine (from 1.95 to 0.89 mg) compared with placebo (from 1.38 to 0.37 mg: p < 0.01). After the season, no difference in PD20 methacholine was found between treatment groups. CONCLUSIONS: The results of this study indicate that fluticasone propionate is effective in decreasing nasal symptoms and eosinophil inflammation in patients with seasonal allergic rhinitis after high-load pollen exposure. Our results also demonstrate that treatment with fluticasone propionate partially prevents the increase in bronchial responsiveness provoked by the inhalation of seasonal pollens in allergic rhinitis.

Administration, Intranasal↗
PubMed1994

Medical and legal problems in intermediate intensive units.

Due to a lack of legislation on the subject (the only data concerns the standard of hospital personnel in the Ministerial Decree (DM) of 13th September 1988), the medical and legal problems are concerned, in the first instance, with defining the type of unit, the context within which it can be placed and the eventual access to essential services and minimum equipment. With regard to responsibility, bearing in mind that the medical team of the intermediary unit (as with all other hospital teams) is employed by the public National Health Service, medical malpractice can be associated with lack of equipment and an inadequate public health service, which is often the cause. If penal responsibility is strictly personal (art. 27 of the Constitution) the civil relationship is, on the one hand, a relationship between the administration and the patient (the physician as employee must give his services within the Health Service and does not have an official personal relationship with the patient) so the Hospital organisation has a contractual type of civil responsibility whereas the employed doctors have an extra-contractual responsibility with different obligations. These responsibilities, which are also determined by the functions of the physician within the USL Health Service (DPR n. 761/1979), can also include control of non-medical staff, control of the equipment, specific training of personnel, etc. Problems concerning the admission of patients to the intermediate unit must also be taken into account (precise evaluation of the indications and of the type of patient to be admitted, refusal of patients in such a condition as to require intensive care or invasive techniques.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMed1993

Bronchial responsiveness to ultrasonic fog in occupational asthma due to toluene diisocyanate.

To determine the validity of ultrasonic nebulization of distilled water (UNDW, "fog") in comparison with methacholine challenge, in the assessment of toluene diisocyanate (TDI) asthma, we evaluated 75 subjects exposed to TDI with work-related respiratory symptoms. Subjects were submitted to bronchial challenge with methacholine at first, thereafter to UNDW inhalation and to specific challenge with TDI. The diagnosis of TDI-asthma was made in 30 of 75 patients (40 percent) who developed a bronchoconstrictive response to the specific challenge (reactors). Sensitivity and specificity of UNDW alone, methacholine alone, and of the combination of the two tests were determined with the results of the specific challenge with TDI as the "gold standard." Both frequency and severity of bronchoconstrictive response to UNDW (FEV1 decrease > or = 15 percent) and the degree (PD15 FEV1) and frequency of bronchial hyperresponsiveness to methacholine were significantly higher in TDI reactors than in nonreactors. The UNDW had higher specificity (82.2 percent vs 51.1 percent) but lower sensitivity (40 percent vs 76.7 percent) than methacholine. The combination in parallel (positivity of any of the two challenges) of methacholine and UNDW challenge did not change sensitivity to a great extent (80 percent vs 76.7 percent), whereas combination in series (positivity of both challenges) had considerably greater specificity (86.7 percent vs 51.1 percent) than methacholine alone. We conclude that in the assessment of TDI-asthma, the validity of UNDW challenge alone is limited since it is insufficiently sensitive. Instead, combining UNDW and methacholine challenge when methacholine is positive improves our ability in identifying subjects with TDI-asthma diagnosed with the specific challenge. This procedure constitutes a first objective confirmation of a suggestive history of TDI-asthma that is useful for clinical purposes. However, especially for medicolegal purposes, the definitive diagnosis requires the specific challenge.

Adult↗
PubMed1986

[Nasal and bronchial respiratory pathology in a group of workers exposed to phthalic anhydride].

Each subject answered a questionnaire, and was submitted to respiratory function tests, bronchial challenge with methacholine and ultrasonic "fog", specific challenge with fumes and powder of PA, measuring nasal and bronchial resistances at the same time by means of a plethysmograph. Serum specific IgE against PA were assessed by the method E.L.I.S.A. Inhalation of "fog" induced a positive nasal response (i.e. nasal resistance increase greater than 70% from baseline) in 73.7% of the subjects, whereas only 3 subjects had a positive bronchial response; specific challenge with PA induced a positive nasal response in 75% out of the subjects, whereas a positive bronchial response was observed in only one subject. 22.7% of the subjects had bronchial hyperreactivity to methacholine. In none of the subjects specific IgE against PA were detectable. We conclude that PA acts as an aspecific irritative agent of airways, particularly of nasal airways.

Airway Resistance↗
PubMed1986

Non-specific nasal reactivity: a proposed method of study.

To test a method for assessing non-specific nasal hyperreactivity, we submitted 23 allergic rhinitis sufferers, 12 normal subjects, 2 patients with asthma and 3 patients with asthma and rhinitis to bronchial challenge with ultrasonic fog (UNDW), recording nasal resistance (NR) and specific bronchial conductance (sGaw) simultaneously by means of a plethysmograph. A significant post-challenge NR increase was observed in 19 of the 23 rhinitis patients, in every patient with asthma and rhinitis, but in only 2 of the 12 normals and in none of the patients with asthma. There was no disturbing increase of nasal secretion. A significant post-challenge sGaw decrease was observed in all the asthmatics and in the patients with asthma and rhinitis, but only in 1 of the 12 normals and in 3 of the 23 rhinitis patients. We conclude that bronchial UNDW could be a suitable method for assessing both nasal and bronchial hyperreactivity.

Adult↗
PubMed1983

Protective effect of nifedipine upon specific bronchial responses to isocyanates.

In order to evaluate the effect of nifedipine, a calcium channel blocker, upon specific bronchial responses to isocyanates, 5 subjects with occupational asthma due to TDI were examined. Each subject was exposed to an atmosphere containing 0.01 ppm of TDI in an inhalation chamber for 15 minutes; the test was repeated on a different day 45 minutes after administration of placebo or nifedipine (20 mg sublingually) in a random fashion. Our data show an effectiveness of nifedipine at the above mentioned dose in preventing the responses arising immediately or within one hour after the exposure (cases n. 1, 2, 3, 4, 5). For preventing late responses it was necessary to repeat the administration of nifedipine (10 mg sublingually) 2 hours after the exposure (cases n. 4 and n. 5). The mechanism by which nifedipine prevents bronchial responses to isocyanates has not been elucidated.

Adult↗
PubMed1981

[Clinical trials of a new preparation in chronic bronchopneumopathies].

The new preparation Broncaspin (guacetisal) has been experimented in the form of 1.2 g suppositories and 5% suspension, in 40 patients suffering from chronic bronchopneumopathy at acute phase. The drug exerted a marked therapeutic action in objective and subjective symptomatology in 87.5% of cases. The action was manifold in relation to the typical expectorant fluidifying, bronchiole disobstructing and anti-inflammatory characteristics of the drug. Tolerance was always excellent.

Adult↗