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Biomedical subjects

W E Pierson

Publications and source records attributed to W E Pierson.

At least 55 records · Page 3Linked to original sources
PubMed1987

The effects of albuterol on sulfur dioxide-induced bronchoconstriction in allergic adolescents.

Ten allergic subjects with exercise-induced bronchospasm were studied to determine whether albuterol could prevent sulfur dioxide (SO2)-induced bronchoconstriction. Albuterol or placebo (180 micrograms) were administered by metered-dose inhaler 20 minutes before a 10-minute exposure to SO2 or clean air during moderate exercise on a treadmill at an exercise level that by itself did not produce exercise-induced bronchospasm. Pulmonary functions (FEV1 and total respiratory resistance [RT]) were measured before the drug, after the drug, and after exposure to SO2 or clean air. Albuterol treatment produced significant bronchodilation and also prevented SO2-induced bronchoconstriction. Following SO2 inhalation after placebo, FEV1 decreased 15% (p less than 0.02) and RT increased 50% (p less than 0.03). Following SO2 inhalation after albuterol treatment, neither FEV1 or RT changed significantly. We conclude that albuterol, a beta 2-agonist, inhibits SO2-induced bronchoconstriction. This result suggests that the adrenergic nervous system or mast cell degranulation are involved in SO2-induced bronchoconstriction.

Adolescent↗
PubMed1987

The effects of ozone and nitrogen dioxide on pulmonary function in healthy and in asthmatic adolescents.

The aim of this project was to investigate whether well-characterized asthmatic adolescent subjects were more sensitive to the inhaled effects of oxidant pollutants than were well-characterized healthy adolescent subjects. Ten healthy and 10 asthmatic subjects inhaled via a mouth-piece 0.12 or 0.18 ppm of ozone (O3) or nitrogen dioxide (NO2) or clean air for 30 min at rest followed by 10 min during moderate exercise (32.5 L/min) on a treadmill. The following pulmonary functional values were measured before and after exposure: peak flow, total respiratory resistance (RT), maximal flow at 50 and 75% of expired VC, and FEV1. After exercise exposure to 0.18 ppm O3, statistically significant increases were seen in RT in asthmatic and healthy adolescent subjects. No consistent changes were seen in either group after NO2 exposure. Also, no significant differences in response to oxidant pollutants between the 2 groups could be demonstrated. It was concluded that neither group was consistently sensitive to these pollutants.

Adolescent↗
PubMed1986

Application of stable isotope methodology in the evaluation of sustained-release theophylline dosage forms.

We compared the kinetics of a single daily dosage form of theophylline (Theo-24) with the kinetics of a twice daily dosage form (Theo-Dur) while we controlled for intrasubject variation in theophylline clearance by use of stable isotope-labeled intravenous theophylline. The stable isotope methodology allowed correction for changes in patient clearance, which allowed more precise estimates of the bioavailability characteristics of these sustained-release theophylline products.

Biological Availability↗
PubMed1986

Bitolterol mesylate in exercise-induced asthma.

Exercise-induced asthma is a useful model for evaluating the activity and duration of action of pharmacologic agents of asthma. The main objective of this double-blind, crossover study was to determine the effect of the aerosolized beta-adrenergic agent, bitolterol mesylate, on exercise-induced asthma while its efficacy was being compared with isoproterenol and placebo. Twelve subjects with exercise-induced asthma performed cycloergometer exercise 45 minutes after three inhalations of bitolterol mesylate aerosol (1050 micrograms), or isoproterenol (255 micrograms), or placebo in random sequence. Bitolterol mesylate aerosol was very effective in protecting against exercise-induced asthma. The mean percent maximal decrease of FEV1 after exercise was 5.0% for bitolterol, 22.2% for isoproterenol, and 23.2% for placebo. Subjects experienced skeletal muscle tremor with both bitolterol mesylate (four subjects) and isoproterenol (three subjects), but not with placebo. No other side effects were noted.

Adolescent↗
PubMed1986

Blinded comparison of maxillary sinus radiography and ultrasound for diagnosis of sinusitis.

The correlation of Waters view radiographs and A-mode ultrasound for diagnosing sinusitis was evaluated in 75 subjects with allergic rhinitis who presented with signs and symptoms suggesting sinus disease. All patients had Waters view radiographs, which were read by a radiologist (E. G.) who was not provided with historical information. Ultrasound tracings were obtained by registered nurses who were trained to perform this procedure. Tracings were interpreted by two representatives of American Electromedics Corporation, the manufacturer of the Echosine ultrasound machine used in this study. Most common symptoms among the patients were cough and rhinorrhea. The complaint of headache correlated negatively (p = 0.001) with an abnormal radiograph, whereas physical findings of copious and purulent rhinorrhea correlated positively (p = 0.05 and 0.001, respectively). Middle ear abnormalities on examination and tympanometry were more common in those with abnormal radiographs, p less than 0.05 and p less than 0.01, respectively. If the radiograph is considered to be a "gold standard," sensitivity of ultrasound varied from 44% to 58% and specificity from 55% to 61%, dependent on which criteria are applied to the radiograph to consider it normal. A-mode ultrasound is not sufficiently comparable to radiography to be used as its substitute for diagnosing sinus disease.

Adolescent↗
PubMed1986

Implications of air pollution effects on athletic performance.

Both controlled human studies and observational studies suggest that air pollution adversely affects athletic performance during both training and competition. The air pollution dosage during exercise is much higher than during rest because of a higher ventilatory rate and both nasal and oral breathing in the former case. For example, sulfur dioxide, which is a highly water-soluble gas, is almost entirely absorbed in the upper respiratory tract during nasal breathing. However, with oral pharyngeal breathing, the amount of sulfur dioxide that is absorbed is significantly less, and with exercise and oral pharyngeal breathing a significant decrease in upper airway absorption occurs, resulting in a significantly larger dosage of this pollutant being delivered to the tracheobronchial tree. Recently, several controlled human studies have shown that the combination of exercise and pollutant exposure (SO2 or O3) caused a marked bronchoconstriction and reduced ventilatory flow when compared to pollution exposure at rest. In a situation like the Olympic Games where milliseconds and millimeters often determine the success of athletes, air pollution can be an important factor in affecting their performance. This paper examines possible impacts of air pollution on athletic competition.

Air Pollution↗
PubMed1985

Induction of eustachian tube dysfunction with histamine nasal provocation.

This study assessed changes in nasal airway resistance and nasal airway power as well as eustachian tube function after histamine nasal provocation in 12 atopic subjects and 10 nonatopic subjects. Results demonstrated that subjects could not be placed in the atopic or nonatopic group on the basis of prechallenge nasal resistance and power measurements. Atopic subjects demonstrated a statistically significant difference in nasal airway power after histamine provocation (p less than 0.05). Nine of 12 atopic subjects demonstrated tympanometric changes indicative of eustachian tube dysfunction, whereas none of 10 nonatopic subjects had these changes (p less than 0.001). These results suggest a differential sensitivity of nonatopic and atopic individuals to histamine, which may be an important pathogenetic mechanism leading to the development of eustachian tube dysfunction and possible subsequent development of otitis media with effusion in the atopic group.

Adult↗
PubMed1985

Albuterol syrup in the treatment of asthma.

This study evaluated the administration of albuterol syrup (0.1 mg/kg/6 hr) or placebo to 2- to 6-year old children whose extrinsic asthma was treated with maintenance theophylline in a prerandomized, double-blind crossover study design. Albuterol/theophylline treatment produced peak expiratory flow rates 2 hours after administration that were significantly higher than in the theophylline/placebo-treated group (119.3 L/min versus 83 L/min) p less than 0.01. The theophylline/placebo-treated group also required higher serum concentrations of theophylline to control wheezing, 10.5 micrograms/ml versus 5.0 micrograms/ml (p less than 0.01). The average symptom scores for the albuterol/theophylline-treated patients (72.5) were less than that of theophylline/placebo-treated group (97.6) p less than 0.02. Side effects such as tremor, irritability, or insomnia occurred in only two of 17 patients. Serial EKG recordings demonstrated no evidence of cardiotoxicity, such as arrhythmias, or indication of myocardial injury. The addition of albuterol to theophylline improved control of severe asthma in children 2 to 6 years of age demonstrated by improvement in pulmonary function, decrease in theophylline dosage requirement, and improvement in symptoms. It was free of any known cardiotoxicity.

Albuterol↗
PubMed1985

The effects of sulfur oxides on nasal and lung function in adolescents with extrinsic asthma.

Ten adolescent subjects with extrinsic asthma were exposed during intermittent exercise to filtered air, 0.5 ppm of sulfur dioxide (SO2), or 100 micrograms/m3 of sulfuric acid (H2SO4) on 5 separate days. The purpose of the study was to compare changes in nasal power (the work of nose breathing) with pulmonary functional changes depending on the route of inhalation of the sulfur oxide pollutants, oral inhalation through a rubber mouthpiece or oronasal inhalation via a face mask. Nasal power was measured with a modified skin diving mask equipped with two differential pressure transducers. Statistically significant changes in total respiratory resistance, FEV1, and maximum flow calculated at 50% and 75% vital capacity were observed after all exposures to SO2 and H2SO4. The magnitude of change in FEV1 and maximum flow calculated at 50% vital capacity was higher after oral compared to oronasal inhalation of SO2. The nasal work of breathing increased 32% after SO2 exposure by mouthpiece and 30% after SO2 exposure via face mask (p less than 0.05). The nasal power changes after the H2SO4 exposures were not different from the sham exposures. We conclude that oronasal inhalation of 0.5 ppm of SO2 produces a significant increase in the nasal work of breathing and that the route of exposure reduces but does not eliminate the lower airway reactions observed on oral exposure.

Adolescent↗
PubMed1985

Acute effects of 0.12 ppm ozone or 0.12 ppm nitrogen dioxide on pulmonary function in healthy and asthmatic adolescents.

Adolescent asthmatic subjects have been shown to be much more sensitive than healthy adolescents to the inhaled effects of sulfur dioxide. To test whether similar adolescent asthmatics are more sensitive to other common ambient air pollutants, 10 healthy and 10 asthmatic adolescent subjects were exposed for 60 min to filtered air, 0.12 ppm ozone (O3), and 0.12 ppm nitrogen dioxide (NO2) on separate days at rest. The following pulmonary functional values were measured before, at 30 min, and after 60 min of exposure: peak flow, total pulmonary resistance (RT), thoracic gas volume at functional residual capacity (FRC), maximal flow at 50 and 75% of expired vital capacity (Vmax50 and Vmax75), and forced expiratory volume in one second (FEV1). Following 60 min of exposure at rest to low concentrations of O3 or NO2, there were no consistent significant functional changes in either healthy or asthmatic adolescent subjects. There also were no measurable differences between the 2 groups.

Adolescent↗
PubMed1985

Identification of exercise-induced asthma among intercollegiate athletes.

Nine hundred eight-three new intercollegiate athletes were evaluated to estimate the frequency of exercise-induced asthma (EIA). Medical history was obtained using a specifically structured interview. Athletes were selected for exercise testing based on positive responses to questions regarding symptoms of respiratory distress after strenuous exercise. Exercise testing was performed in a controlled laboratory setting using a standard exercise protocol. A laboratory diagnosis of EIA was made if the forced expiratory volume in one second (FEV1) fell greater than or equal to 10%, forced expiratory flow at 25% to 75% of vital capacity (FEF25-75%) fell greater than or equal to 20%, and/or peak expiratory flow rate (PEFR) fell greater than or equal to 12.5% after exercise. The frequency of EIA was 2.8%; only nine of the 28 athletes with EIA were detected prior to arrival at college.

Adolescent↗
PubMed1984

Air pollutants, bronchial hyperreactivity, and exercise.

The interaction of air pollutants and their effect on bronchial hyperreactivity show that sulfur dioxide and ozone both increase bronchial hyperreactivity. Sulfur dioxide concentrates as low as 0.5 ppm and ozone concentrations as low as 0.2 ppm have demonstrated this effect. Exercise with either sulfur dioxide or ozone exposure can significantly increase bronchial hyperreactivity in susceptible individuals. Other factors including ambient air temperature, time of day, wind velocity and direction, geography, climate, tobacco smoke exposure, and other indoor air pollutants may enhance the impact of air pollutants, causing bronchial hyperreactivity.

Adaptation, Physiological↗
PubMed1984

A double-blind study comparing the effectiveness of cromolyn sodium and sustained-release theophylline in childhood asthma.

The effectiveness of cromolyn sodium and theophylline on asthma in children was compared during a 3-month trial. Forty-six children (aged 5 to 15 years) with asthma were assigned at random to cromolyn or theophylline (Theo-Dur) treatment groups. Each subject received theophylline placebo or cromolyn placebo in addition to the active drugs. A methacholine challenge test was done at the start of the study to document asthma and was repeated during the third month. The theophylline dosage was regulated to obtain serum levels of 10 to 15 micrograms/mL by a physician not involved directly with patient care. Forty patients completed the study. Both theophylline and cromolyn treatment groups showed improvement from base-line status in terms of symptom scores, pulmonary function, and decreased use of inhaled albuterol. Patients treated with theophylline had more side effects and required more frequent office visits than those treated with cromolyn. Both groups had decreased sensitivity to methacholine, and for one statistical test patients treated with cromolyn improved significantly. These results indicate that cromolyn is as effective as theophylline in treating mild to moderate asthma in children; additional benefits were fewer side effects and a possible decrease in bronchial hyperactivity.

Adolescent↗
PubMed1984

Facial characteristics of children who breathe through the mouth.

There are many claims that abnormal breathing patterns alter facial growth; however, there are limited controlled data to confirm these claims. Thirty children with allergy, aged 6 to 12 years, who had moderate-to-severe nasal mucosal edema on physical examination and who appeared to breathe predominantly through the mouth and 15 children without allergy who had normal findings from nasal examination and who appeared to breathe predominantly through the nose were evaluated. All subjects received an intraoral clinical examination and cephalometric radiograph analysis. In comparison with children who breathed through the nose, children who breathed through the mouth had longer faces with narrower maxillae and retruded jaws. This supports the hypothesis that children with nasal obstruction and who appear to breathe through the mouth have distinctive facial characteristics.

Cephalometry↗