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Biomedical subjects

J E Fish

Publications and source records attributed to J E Fish.

84 records · Page 5Linked to original sources
PubMed1979

Effect of environmental exposure on bronchial sensitivity to antigen.

Bronchial sensitivity to grass and ragweed extracts was determined in four adult asthmatic subjects at the beginning and end of the grass and ragweed pollen seasons. 4 subjects with ragweed sensitivity had increased bronchial sensitivity to ragweed antigen at the end of the ragweed season. 2 of 3 grass sensitive subjects demonstrated increased bronchial sensitivity to grass antigen after the grass pollen season. This study suggests that natural environmetnal exposure to pollen antigens may induce priming in the lung.

Adult↗
PubMed1977

Methacholine and physostigmine airway reactivity in asthmatic and nonasthmatic subjects.

Inhalation challenges using methacholine and physostigmine were performed in 3 human asthmatic and 3 nonallergic normal subjects. Plethysmographic measurements of specific airways conductance (Gaw/Vtg) were used to monitor the response. The dose required to produce a 17% fall in Gaw/Vtg was significantly lower in asthmatic subjects than in normal subjects for both physostigmine (p less than 0.0125) and methacholine (p less than 0.05). Moreover, in all subjects the relative airway sensitivity to methacholine correlated with the relative airway sensitivity to physostigmine. Both methacholine and physostigmine are cholinergic agents. Whereas methacholine acts directly at the end organ cholinergic receptor, physostigmine acts by increasing release and decreasing destruction of endogenous acetycholine at the vagal distal innervation. This suggests that the cholinergic airway hyperreactivity characteristic of asthma is a manifestation of end organ hypersensitivity.

Acetylcholine↗
PubMed1977

Effect of deep inspiration on airway conductance in subjects with allergic rhinitis and allergic asthma.

We measured specific airway conductance (Gaw/Vtg) in a body plethysmograph before and after a deep inspiratory maneuver in 8 subjects with allergic rhinitis and 8 subjects with allergic asthma. In hay fever subjects deep inspiration had no effect on Gaw/Vtg if it was performed in the control state; however, when methacholine-induced bronchoconstriction was present, deep inspiration transiently increased Gaw/Vtg. In asthmatic subjects deep inspiration was followed by a transeint fall in baseline Gaw/Vtg in the control state; however, when bronchoconstriction was present, deep inspiration was followed by small and variable changes in Gaw/Vtg in 7 subjects and marked improvement in Gaw/Vtg in 1 subject. In asthmatic subjects the bronchoconstrictor response to deep inspiration performed in the control state is thought to be due to reflex changes in bronchomotor tone mediated by cholinergic (vagal) nerve pathways. Like asthmatic subjects, hay fever subjects, hay fever subjects also possess cholinergic-mediated airway hyperreactivity compared with normals. Our results indicate that, in spite of their increased airway reactivity, hay fever subjects respond more like normal subjects than like asthmatic subjects after a deep inspiratory maneuver.

Adult↗
PubMed1977

The effect of atropine on acute antigen-mediated airway constriction in subjects with allergic asthma.

Exposure to antigen by inhalation challenge may produce airway constriction in patients with allergic asthma. To examine the role of reflex bronchoconstriction mediated by the vagus nerve in the antigen-induced airway response, we compared the responses of 6 asthmatic volunteers to inhaled ragweed antigen alone and to antigen given after pretreatment with atropine sulfate, a parasympathetic blocking agent. We found significant increases in airway resistance, limitation of parasympathetic blocking agent. We found significant increases in airway resistance, limitation of forced expiratory flow, increases in lung volumes, and alterations in the distribution of inspired gas after antigen was given. When subjects were pretreated with atropine, we found a mean increase in the 1-sec forced expired volume of 0.380 liter (P less than 0.025) and a mean increase in specific airway conductance of 0.067 sec-1-cm H2O-1 (P less than 0.005). Atropine pretreatment did not prevent the responses to antigen in our subjects. After atropine pretreatment subjects began the antigen challenge with better pulmonary function and at a given antigen dose maintained a better level of function compared to when antigen was given alone. Differences in the absolute level of pulmonary function between the two challenges became smaller with the administration of larger antigen doses. We conclude that reflex bronchospasm involving postganglionic efferent parasympathetic nerve pathways is not a major component of the response to inhaled antigen in human allergic asthma.

Adult↗
PubMed1976

Airway responses to methacholine in allergic and nonallergic subjects.

After inhalation challenge with methacholine, bronchoconstrictor responses were produced in allergic subjects with asthma and hay fever as well as nonallergic subjects. Our results indicate that allergic persons possess a greater pulmonary responsiveness to inhalation of this parasympathomimetic agent than nonallergic subjects; however, patterns of response were different in the 2 types of allergic subjects, those with asthma and those with hay fever. Whereas both types of allergic subjects responded with changes in specific airway conductance when nonallergic subjects did not, only asthmatic subjects differed from nonallergic subjects when comparisons of spirometry were made. These data suggest that there is hypersensitivity of both central and peripheral airways in asthmatics and in the larger central airways of nonasthmatic allergic subjects.

Adult↗
PubMedDate not supplied

Long-acting beta2-agonist monotherapy vs continued therapy with inhaled corticosteroids in patients with persistent asthma: a randomized controlled trial.

CONTEXT: Long-acting beta(2)-agonists are prescribed for patients with persistent asthma and are sometimes used without inhaled corticosteroids (ICSs). No evidence exists, however, to support their use as monotherapy in adults with persistent asthma. OBJECTIVE: To examine the effectiveness of salmeterol xinafoate, a long-acting beta(2)-agonist, as replacement therapy in patients whose asthma is well controlled by low-dose triamcinolone acetonide, an ICS. DESIGN AND SETTING: A 28-week, randomized, blinded, placebo-controlled, parallel group trial conducted at 6 National Institutes of Health-sponsored, university-based ambulatory care centers from February 1997 to January 1999. PARTICIPANTS: One hundred sixty-four patients aged 12 through 65 years with persistent asthma that was well controlled during a 6-week run-in period of treatment with inhaled triamcinolone (400 microg twice per day). INTERVENTIONS: Patients were randomly assigned to continue triamcinolone therapy (400 microg twice per day; n = 54) or switch to salmeterol (42 microg twice per day; n = 54) or to placebo (n = 56) for 16 weeks, after which all patients received placebo for an additional 6-week run-out period. MAIN OUTCOME MEASURES: Change in morning and evening peak expiratory flow (PEF), forced expiratory volume in 1 second (FEV(1)), self-assessed asthma symptom scores, rescue albuterol use, asthma-specific quality-of-life scores, treatment failure, asthma exacerbation, bronchial reactivity, and markers of airway inflammation, compared among the 3 treatment groups. RESULTS: During the 16-week randomized treatment period, no significant differences between the salmeterol and triamcinolone groups were observed for conventional outcomes of clinical studies of asthma therapy-morning PEF, evening PEF, asthma symptom scores, rescue albuterol sulfate use, or quality of life. Both active treatments were superior to placebo. However, the salmeterol group had more treatment failures than the triamcinolone group (13/54 [24%] vs 3/54 [6%]; P =.004), as well as more asthma exacerbations (11/54 [20%] vs 4/54 [7%]; P =.04), greater increases in median (interquartile range) sputum eosinophils (2.4% [0.0% to 10.6%] vs -0.1% [-0.7% to 0.3%]; P<.001), eosinophil cationic protein (71 [-2 to 430] U/L vs -4 [-31 to 56] U/L; P =.005), and tryptase (3.1 [2.1 to 7.6] ng/mL vs 0.0 [0.0 to 0.7] ng/mL; P<.001). The duration of benefit when patients were switched from active treatment to placebo after 22 weeks of randomized treatment was not significantly longer in the triamcinolone group than in the salmeterol group. CONCLUSIONS: Patients with persistent asthma well controlled by low doses of triamcinolone cannot be switched to salmeterol monotherapy without risk of clinically significant loss of asthma control.

Administration, Inhalation↗
PubMedDate not supplied

Inhaled corticosteroid reduction and elimination in patients with persistent asthma receiving salmeterol: a randomized controlled trial.

CONTEXT: Inhaled long-acting beta(2)-agonists improve asthma control when added to inhaled corticosteroid (ICS) therapy. OBJECTIVE: To determine whether ICS therapy can be reduced or eliminated in patients with persistent asthma after adding a long-acting beta(2)-agonist to their treatment regimen. DESIGN AND SETTING: A 24-week randomized, controlled, blinded, double-dummy, parallel-group trial conducted at 6 National Institutes of Health-sponsored, university-based ambulatory care centers from February 1997 through January 1999. PARTICIPANTS: One hundred seventy-five patients aged 12 through 65 years with persistent asthma that was suboptimally controlled during a 6-week run-in period of treatment with inhaled triamcinolone acetonide (400 microg twice per day). INTERVENTION: Patients continued triamcinolone therapy and were randomly assigned to receive add-on therapy with either placebo (placebo-minus group, n = 21) or salmeterol xinafoate, 42 microg twice per day (n = 154) for 2 weeks. The entire placebo-minus group was assigned and half of the salmeterol group (salmeterol-minus group) was randomly assigned to reduce by 50% (for 8 weeks) then eliminate (for 8 weeks) triamcinolone treatment. The other half of the salmeterol group (salmeterol-plus group) was randomly assigned to continue both salmeterol and triamcinolone for the remaining 16 weeks (active control group). MAIN OUTCOME MEASURE: Time to asthma treatment failure in patients receiving salmeterol. RESULTS: Treatment failure occurred in 8.3% (95% confidence interval [CI], 2%-15%) of the salmeterol-minus group 8 weeks after triamcinolone treatment was reduced compared with 2.8% (95% CI, 0%-7%) of the salmeterol-plus group during the same period. Treatment failure occurred in 46.3% (95% CI, 34%-59%) of the salmeterol-minus group 8 weeks after triamcinolone therapy was eliminated compared with 13.7% (95% CI, 5%-22%) of the salmeterol-plus group. The relative risk (95% CI) of treatment failure at the end of the triamcinolone elimination phase in the salmeterol-minus group was 4.3 (2.0-9.2) compared with the salmeterol-plus group (P<.001). CONCLUSIONS: Our results indicate that in patients with persistent asthma suboptimally controlled by triamcinolone therapy alone but whose asthma symptoms improve after addition of salmeterol, a substantial reduction (50%) in triamcinolone dose can occur without a significant loss of asthma control. However, total elimination of triamcinolone therapy results in a significant deterioration in asthma control and, therefore, cannot be recommended.

Administration, Inhalation↗
PubMedDate not supplied

Zafirlukast for symptomatic mild-to-moderate asthma: a 13-week multicenter study. The Zafirlukast Trialists Group.

The efficacy of the oral leukotriene-receptor antagonist zafirlukast was assessed as maintenance therapy for patients with mild-to-moderate asthma. A total of 762 patients aged 12 to 76 years were enrolled in a 13-week, multicenter, double-masked, placebo-controlled, parallel-group trial and randomly assigned to receive either zafirlukast (20 mg twice daily) or placebo. Patients were maintained on as-needed beta-agonist therapy throughout the study and had to have a cumulative daytime asthma symptoms score > or = 8 (on a daily scale of 0 to 3) over 7 consecutive days before randomization. Efficacy was assessed by changes in symptoms, beta-agonist use, and pulmonary function. Safety was assessed by adverse experiences, laboratory test results, physical examination, and electrocardiography. Zafirlukast significantly decreased daytime asthma symptoms scores (-26.5%), nighttime awakenings (-19.8%), mornings with asthma (-29.0%), and beta-agonist use (-22.3%) and significantly increased morning peak expiratory flow rate (6.9%) and forced expiratory volume in 1 second (6.3%) compared with placebo. Changes in symptoms, beta-agonist use, and pulmonary function occurred within 2 days of zafirlukast treatment and continued throughout the trial. Zafirlukast was well tolerated. Pharyngitis and headache were the most common adverse events, occurring with similar frequency in both the zafirlukast and placebo groups. No clinically significant changes were observed in laboratory test results, findings on physical examination, or electrocardiographic findings. We conclude that zafirlukast produces early and sustained effects in the treatment of mild-to-moderate asthma.

Adolescent↗
PubMedDate not supplied

Effect of polymorphism of the beta(2)-adrenergic receptor on response to regular use of albuterol in asthma.

BACKGROUND: Regular use of inhaled beta-adrenergic agonists may have adverse effects in some asthma patients. Polymorphisms of the beta(2)-adrenergic receptor (beta(2)-AR) can affect its regulation; however, results of smaller studies of the effects of such polymorphisms on response to beta-agonist therapy have been inconsistent. METHODS: We examined the possible effects of polymorphisms at codons 16 (beta(2)-AR-16) and 27 (beta(2)-AR-27) on response to albuterol by genotyping 190 asthmatics who had participated in a trial of regular versus as-needed albuterol use. RESULTS: During the 16-week treatment period, patients homozygous for arginine (Arg/Arg) at beta(2)-AR-16 who used albuterol regularly had a small decline in morning peak expiratory flow (AM PEF). This effect was magnified during a 4-week run-out period, when all patients returned to as-needed albuterol only. By the end of the study, Arg/Arg subjects who had used albuterol regularly had an AM PEF 30.5 +/- 12.1 liters/min lower (p = 0.012) than Arg/Arg patients who had used albuterol as needed only. Subjects homozygous for glycine at beta(2)-AR-16 showed no such decline. Evening PEF also declined in the Arg/Arg regular but not in as-need albuterol users. No significant differences between regular and as-needed treatment were associated with polymorphisms at beta(2)-AR-27. CONCLUSIONS: Polymorphisms of the beta(2)-AR may influence airway responses to regular inhaled beta-agonist treatment.

Adolescent↗