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Biomedical subjects

F E Hargreave

Publications and source records attributed to F E Hargreave.

At least 19 recordsLinked to original sources
PubMed1992

A research method to induce and examine a mild exacerbation of asthma by withdrawal of inhaled corticosteroid.

This study evaluated a research method to examine an exacerbation of asthma induced by corticosteroid withdrawal. Ten non-smoking adult asthmatics who were stable on treatment with inhaled steroid underwent a graded reduction of the daily dose by 200 micrograms at weekly intervals until an exacerbation of symptoms occurred. A daily symptom, peak expiratory flow rate (PEF) and medication diary was kept. Weekly clinic visits were used to assess symptoms, spirometry, methacholine airway responsiveness (expressed as the provocative concentration to cause a fall in FEV1 of 20%, PC20), circulating eosinophils, basophils and their progenitors (Eo/B-CFU), and sputum inflammatory cells. The laboratory tests were performed blind to the clinical details. Each subject developed an exacerbation of symptoms, on average at 16 (7-26) days after the onset of steroid reduction. This was accompanied by a deterioration in each of the objective measures. There was a fall in FEV1 by 320 ml (s.e.m. 9.5) and in PC20 from 0.8 to 0.43 mg/ml. Circulating eosinophils rose from 114 (24) x 10(3)/ml to 227 (50) x 10(3)/ml and Eo/B-CFU rose from 31 (5.6) to 44 (11.3)/10(6) cells. Sputum developed in five subjects and contained 36 (5.2)% eosinophils and 1.98 (0.21)% metachromatic cells (mast cells or basophils). The symptom diary and weekly questionnaire were demonstrated to be valid and responsive to change. A deterioration indicated by the daily symptom score preceded changes in PEF. Treatment by an increase in steroid was followed by reversal of each of the changes.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗
PubMed1992

Use of induced sputum cell counts to investigate airway inflammation in asthma.

BACKGROUND: Airway inflammation is considered to be important in asthma but is relatively inaccessible to study. Less invasive methods of obtaining sputum from patients unable to produce it spontaneously should provide a useful investigational tool in asthma. METHODS: A method to induce sputum with inhaled hypertonic saline was modified for use in 17 asthmatic patients and 17 normal subjects who could not produce sputum spontaneously. The success rate and safety of the method, the reproducibility of cell counts, and differences in cell counts between the asthmatic and normal groups were examined. Hypertonic saline solution 3-5% was inhaled for up to 30 minutes after inhalation of salbutamol. Subjects were asked to expectorate sputum every five minutes. The quality of the sample was scored on the volume of plugs and the extent of salivary contamination. Plugs from the lower respiratory tract were selected for a total cell count and for differential cell counts of eosinophils and metachromatic cells (mast cells and basophils) in direct smears. RESULTS: Adequate samples from the lower respiratory tract were obtained in 76% of first attempts. The mean fall in the forced expiratory volume in one second (FEV1) during inhalation of saline was 5.3% and the maximum fall 20%. Eosinophil and metachromatic cell counts were reproducible (reliability coefficient 0.8 and 0.7 respectively). When compared with sputum from normal subjects sputum from asthmatic patients contained a significantly higher proportion of eosinophils (mean 18.5% (SE 3.8%) v 1.9% (0.6%)) and metachromatic cells (0.50% (0.18%) v 0.039% (0.014%)). In the asthmatic group the differential eosinophil count correlated with the baseline FEV1. CONCLUSION: Induced sputum is capable of detecting differences in cell counts between normal and asthmatic subjects and merits further development as a potential means of assessing airway inflammation in asthma.

Adolescent↗
PubMed1992

Changes in the cellular profile of induced sputum after allergen-induced asthmatic responses.

Allergen inhalation causes airway inflammation and an increase in histamine airway responsiveness. We have used cell counts in sputum induced by hypertonic saline aerosol to assess airway inflammation before and 32 h after asthmatic responses to allergen. Twelve asthmatic subjects (mean age, 27.4 yr; range, 20-38 yr) had an inhalation test with D. farinae, ragweed pollen, or cat extract. All of them developed an early response with a fall in FEV1, of 24.8% (SD, 6.3%); nine of 12 had a definite late response (fall in FEV1 greater than or equal to 15%), and 10 of 12 had an increase in airway responsiveness to histamine at 32 h (PC20 reduced by greater than twofold). Sputum was induced by hypertonic saline after the histamine test, before and 32 h after the allergen challenge, at the same time of day. The quality of the sample was scored according to visual inspection and inverted microscopy and by salivary contamination. Plugs arising from the lower respiratory tract were selected for further evaluation. Differential cell counts of eosinophils (Eo) and metachromatic cells (MCC) (mast cell and basophils) were obtained from direct smears, blind to the clinical procedures. The mean fall in FEV1 after hypertonic saline was 6.4% (range, zero to 28%). The sputum samples were adequate in 79.5% of attempts. Eo and MCC increased significantly from 3.8 (4.4) to 18.2 (22.8)% (p = 0.01) and from 0.05 (0.17) to 0.25 (0.76)% (p = 0.04), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Formoterol compared with beclomethasone and placebo on allergen-induced asthmatic responses.

Formoterol is a new long-acting beta 2-agonist. We compared the protective effect of 24 micrograms formoterol with 200 micrograms beclomethasone and placebo on inhaled allergen-induced asthmatic responses in mild stable asthmatic subjects. We measured airflow rates, histamine airway responsiveness, cell counts from sputum and peripheral blood, and markers of lymphocyte and eosinophil activation. Adjustments were made for the confounding effect of bronchodilatation produced by formoterol in comparisons using a control inhalation of normal saline. Formoterol caused bronchodilation and inhibition of histamine airway responsiveness for at least 24 h. It completely inhibited the early asthmatic responses when beclomethasone had no effect. Control comparisons of the effect of formoterol and beclomethasone on the allergen-induced late asthmatic response and increase in histamine responsiveness showed each to be equally effective but not to inhibit the responses completely. Formoterol caused bronchodilation in addition to preventing bronchoconstriction. Both drugs inhibited the rise in serum eosinophil cationic protein 24 h after allergen, but neither inhibited the allergen-induced increases in sputum or blood eosinophils or CD25+ lymphocytes. These results suggest that formoterol modifies allergen-induced airway responses through functional antagonism rather than the inhibition of inflammatory cell infiltration.

Adult↗
PubMed1991

Reduction of budesonide after a year of increased use: a randomized controlled trial to evaluate whether improvements in airway responsiveness and clinical asthma are maintained.

We have demonstrated recently that 1 year of regular inhaled budesonide use can produce substantial improvements in airway responsiveness accompanied by significant improvements in clinical asthma severity. The present study was designed to evaluate whether these improvements are maintained when the dose of budesonide is reduced. At the end of the original study, 28 subjects with asthma, who had been in the active-treatment arm of the study were randomized either to continue taking the dose of budesonide taken in the original study or to have the dose reduced. Airway responsiveness to methacholine, bronchodilator requirements, symptoms, and spirometry were assessed after 6 weeks and 3 months. During the 3 months, no subject experienced an asthma exacerbation, and there was no evidence of change in airway responsiveness in subjects who had their steroids reduced (provocative concentration causing a 20% drop in FEV1; initial, 2.03 mg/ml; final, 1.91 mg/ml), and this change was not different from change in subjects maintained with a higher dose (initial, 3.02 mg/ml; final, 3.12 mg/ml) (p = 0.39). Similarly, there was no evidence of any change in bronchodilator requirements (p = 0.89). However, after 3 months of reduced steroid use, there was a small decline in spirometry (FEV1 percent predicted: initial, 84.4%; final, 81.5%), and this change was significantly different from change in subjects in whom steroids were not reduced (initial, 90.2%; final, 90.2%) (p = 0.002). At 3 months, symptoms (predominantly sputum production) were also beginning to redevelop in the reduced budesonide group (p = 0.056).(ABSTRACT TRUNCATED AT 250 WORDS)

Asthma↗
PubMed1991

Allergen-induced asthmatic responses. Relationship between increases in airway responsiveness and increases in circulating eosinophils, basophils, and their progenitors.

The inflammatory response during allergen-induced asthma was assessed using serial measures of peripheral blood eosinophils (Eo), basophils (B), and Eo/B progenitor cells (Eo/B-CFU). A group of 14 stable asthmatic individuals (beta 2-agonists only as needed) had inhalation provocation tests with allergen (18 tests in total) and with diluent. Serial blood samples were taken before and 1 and 24 h after the tests; methylcellulose cultures for Eo/B-CFU and granulocyte-macrophage (GM-CFU) were scored at 14 days. Circulating Eo, B, and Eo/B-CFU were increased at 24 h after allergen inhalation when this resulted in increased histamine airway responsiveness (n = 13). In the 5 subjects with isolated early asthmatic responses the Eo, B, and Eo/B-CFU counts did not change. There was no change in the GM-CFU after allergen. The ratio change in circulating Eo/B-CFU was negatively correlated with baseline histamine airway responsiveness (r = -0.8, p less than 0.05). Four subjects who had an isolated early response and no blood changes to one allergen developed an increase in histamine airway responsiveness and an increase in Eo, B, and Eo/B progenitors after inhalation of a second different allergen. The results indicate that in subjects with an allergen-induced increase in histamine airway responsiveness, an inflammatory response occurs that includes an increase in the number of Eo/B progenitors. This response, possibly mediated by Eo/B growth and differentiation factors, could lead to the accumulation of these cells in the airway and contribute to the airways inflammation present in asthma.

Allergens↗
PubMed1991

Prolonged protection against methacholine-induced bronchoconstriction by the inhaled beta 2-agonist formoterol.

Formoterol fumarate is a new, high-affinity, beta 2-adrenergic receptor agonist that causes bronchodilation for at least 12 h. The purpose of this study was to compare the magnitude and duration of the effect of inhalation of formoterol (12 and 24 micrograms), albuterol (200 micrograms), and placebo in terms of protection against methacholine-induced bronchoconstriction. The 16 stable adult asthmatic subjects were studied on four separate study days. On each study day the subjects inhaled 2 puffs of the study medication, and methacholine tests were performed at 30 min and 4, 8, and 12 h later. Results were expressed as the provocative concentration of methacholine required to cause a 20% fall in FEV1 (PC20). At 30 min, 12 and 24 micrograms formoterol caused a mean 14- to 20-fold decrease in responsiveness, and albuterol a 12-fold decrease. However, albuterol had no significant protective effect at 4 h or thereafter, whereas there was still an 8-fold decrease in responsiveness for 24 micrograms formoterol and a 6-fold decrease for 12 micrograms formoterol at 12 h. This study has shown that both doses of formoterol were still actively protective against induced bronchoconstriction 12 h after inhalation, with minimal side effects. This suggests that formoterol may prove to be a very useful bronchodilator for the treatment of patients with asthma who have significant airway hyperresponsiveness or nocturnal symptoms and who require inhaled beta 2-agonists at least twice daily.

Administration, Inhalation↗
PubMed1990

Acute asthma: emergency department management and prospective evaluation of outcome.

To determine the current management of acute asthma in the emergency department and to evaluate outcome we reviewed the charts of 99 patients aged 15 to 55 years who presented to the emergency department of a tertiary referral, university-affiliated hospital and were subsequently discharged with a diagnosis of acute asthma. Outcome was evaluated prospectively, with a structured questionnaire, by telephone. During the visit pulsus paradoxus was documented in four patients. Spirometry was done in 63 patients; postbronchodilator values ranged from 0.9 to 4.1 L. A total of 92 patients received inhaled bronchodilator therapy, most by wet nebulization. Sixteen patients received anticholinergic agents and three received theophylline. Ingested corticosteroids were given to 27 patients. Of the 71 patients contacted, a mean of 12 days after the visit, 26 (37%) had sought further medical attention, 19 at the emergency department; 9 had required admission. Forty-six patients reported that their condition had improved, but over 60% continued to have cough, sputum production, nocturnal waking and early-morning chest tightness. The results indicate that asthma continues to be undertreated in the emergency department and highlight the importance of routine spirometry in all patients and the need for systemic corticosteroid therapy.

Acute Disease↗
PubMed1990

Sputum cell counts in airway disease: a useful sampling technique.

Quantitative sputum cell counts from patients with asthma and chronic bronchitis were performed and found to be reproducible. Sputum from carefully characterized subjects with asthma contained large numbers of eosinophils and formalin-sensitive metachromatic (mast) cells. In contrast, the macrophage was the dominant cell type in the sputum from smokers with chronic bronchitis. In a third group of patients with corticosteroid responsive-chronic cough and normal methacholine airway responsiveness the sputum contained eosinophils and metachromatic cells, similar to the asthmatic subjects. Sputum cell counts are a useful, noninvasive method for the identification of this pattern of inflammatory response in patients with airway diseases.

Humans↗
PubMed1990

The role of measurements of airway responsiveness.

In smokers with chronic airflow limitation (CAL), airway hyperresponsiveness (AHR) to stimuli like methacholine, which act directly on airway smooth muscle, are not specific for the pathogenesis which is responsible for AHR to methacholine in subjects with normal spirometry, nor predictive for a beneficial effect of glucocorticosteroid (GCS) treatment. In contrast, AHR to stimuli like hyperventilation, which act indirectly through mediator release, may be specific for the pathogenesis of asthma and predictive for a beneficial effect of GCS. The validation of this possibility requires the demonstration that patients with CAL and AHR to hyper-ventilation demonstrate improvement after treatment with GCS (and have an increase in eosinophils and metachromatic cells in the sputum or bronchoalveolar lavage (BAL), like that seen in asthmatics uncomplicated by CAL).

Asthma↗
PubMed1990

Comparison of the efficacy and side effects of aqueous steroid nasal spray (budesonide) and allergen-injection therapy (Pollinex-R) in the treatment of seasonal allergic rhinoconjunctivitis.

The efficacy and side effects of two approaches to the treatment of ragweed pollen-induced rhinoconjunctivitis were compared in a double-blind, parallel-group trial. Sixty ragweed-sensitive adults were randomized either to a course of four Pollinex-R hyposensitization injections during the 6 weeks before the ragweed-pollen season, or to budesonide aqueous nasal steroid spray, 400 micrograms daily, throughout the season. A double-dummy technique was used to achieve blinding. During the ragweed-pollen season, troublesome nasal symptoms were treated with terfenadine, 60 mg, when treatment was needed, up to 240 mg daily, and eye symptoms were treated with naphazoline eye drops, when treatment was needed, up to four times daily. Every day, subjects recorded the severity of nasal and eye symptoms and medication use in a diary. Fourteen of the subjects receiving Pollinex-R were unable to complete the course of injections because of systemic or large local reactions. Eight subjects withdrew during the pollen season because of severe rhinitis; all subjects had received Pollinex-R. Subjects in the budesonide-treated group had minimal nasal symptoms and used very little terfenadine, compared with subjects in the Pollinex-R-treated group (p less than 0.0001). Eye symptoms and eye drop use were similar in the two treatment groups. No clinically important side effects were reported by the subjects receiving budesonide. The results of this study suggest that aqueous budesonide nasal spray is markedly more effective than Pollinex-R in controlling symptoms of seasonal rhinitis while the side effects and inconvenience of immunotherapy are avoided.

Aldehydes↗