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Biomedical subjects

J G Easton

Publications and source records attributed to J G Easton.

12 recordsLinked to original sources
PubMed1990

Effects of histamine on alpha adrenergic receptor expression on the lymphocytes of normal and asthmatic subjects.

Low levels of [3H]-dihydroergocryptine (DHE) (alpha adrenergic receptor) binding to peripheral blood mononuclear leukocytes from asthmatic subjects were significantly increased following incubation with histamine. In contrast, [3H]-DHE binding was undetectable both before and after histamine incubation using cells from nonasthmatic subjects. The change in binding showed a biphasic dose dependence on histamine and was not associated with changes in DHA (beta-2 receptor) or yohimbine (alpha-2 receptor) binding. The induction of alpha adrenergic receptors by the ubiquitous inflammatory mediator histamine may help explain the alpha adrenergic hyperresponsiveness seen in asthmatic patients.

Asthma↗
PubMed1983

Patterns of response to inhaled methacholine.

Fifty-two patients with unexplained pulmonary symptoms were tested using inhaled methacholine. Of the 32 who reacted 11 had a greater than 20% decrease in FEV1 (with or without an associated change in FEF25-75%) as the end-point, 15 had a greater than 25% decrease in FEF25-75% as their initial response while 6 had an initial greater than 25% decrease in FEF200-1200. In some but not all subjects in the latter two groups a decrease in FEV1 occurred with increased methacholine concentrations. Changes in FEF25-75% and FEF200-1200 should be considered in documentation of airway hyperreactivity in some patients.

Adolescent↗
PubMed1981

Effect of an inhaled corticosteroid on methacholine airway reactivity.

Methacholine airway reactivity was studied in seven asthmatic patients before and at the end of 4 mo of beclomethasone dipropionate therapy, as well as in a control group. There was no statistically significant change in reactivity in either group, suggesting that a change in airway cholinergic receptor activity is not part of the mechanism of action of corticosteroids in asthma.

Administration, Intranasal↗
PubMed1979

The value of atropine in the documentation of reversible airways obstruction.

Thirteen randomly selected outpatient asthmatics were treated with nebulized atropine sulfate, isoproterenol and the combination of these drugs in a randomized double-blind trial. Sequential pulmonary function parameters, cardiovascular changes and side effects were monitored over a 60-minute period following drug administration. Both atropine and isoproterenol produced significant and equivalent improvement in mean forced expiratory flow rates; the combination of drugs produced significantly greater improvement at each time interval without producing significant cardiovascular changes or side effects. Four patients failed to show clinically significant increases in expiratory flow rates following isoproterenol alone; two of these four improved following atropine alone, while two improved only when given the combination of drugs. The addition of an anti-cholinergic agent may provide a more precise assessment of reversibility of obstructive airways disease in the individual patient.

Adult↗
PubMed1976

A multifactorial study of patients with asthma. Part 2: air pollution, animal dander and asthma symptoms.

As part of a multifactorial computer-assisted study of patients with asthma, the relationship between air pollution, animal dander and asthma symptoms was evaluated. No association was found between four major air pollutants (carbon monoxide, ozone, nitrogen oxides and sulfur dioxide) and asthma symptoms. Patients who owned cats and dogs reported more severe asthma symptoms (p less than .01) than patients who did not own cats and dogs. The evaluations completed to date indicate that daily exposure to cats and dogs accounts for more of the asthma symptoms differences between patients than daily exposure to air pollutants.

Adolescent↗
PubMed1975

The value of inhalation challenge testing as an office procedure.

One hundred seventy-three bronchial challenge tests were performed as an outpatient procedure on 35 selected clinic patients. The incidence of positive tests was sufficiently high and the procedure tolerated well enough to suggest this as a practical office procedure if carefully done in properly chosen patients.

Adolescent↗