Biomedical subjects

W E Pierson

Publications and source records attributed to W E Pierson.

114 records · Page 7Linked to original sources

PubMedDate not supplied

Effects of inhaled sulfur dioxide (SO2) on pulmonary function in healthy adolescents: exposure to SO2 alone or SO2 + sodium chloride droplet aerosol during rest and exercise.

Recently we reported statistically significant changes in pulmonary functional measurements in asthmatic adolescents exposed at rest or during exercise. To demonstrate whether those results were due to the subjects' adolescence, or more likely, to their diagnosis of asthma, we repeated identical exposures in healthy adolescents. The changes after exposure to sulfur dioxide (SO2); however the changes were only slightly greater than those seen after sham exposure. After exposure at rest to 1.0 ppm SO2 + 1 mg/m3 sodium chloride (NaCl) droplet aerosol, the healthy adolescents showed small (3%) but statistically significant reductions in forced expiratory volume in one second (FEV1.0). No significant changes were seen following exposure to NaCl of SO2 alone at rest. Exposure to the SO2 modes during moderate exercise produced greater changes. Following exposure to either the SO2 + NaCl mixture or 1.0 ppm of SO2 alone, the reductions in FEV1.0 were slightly greater (6%) and prolonged compared with those seen at rest. Significant decreases also were seen in Vmax50 and Vmax75. A small decrease (4%) in FEV1.0 was seen following exposure to NaCl alone during exercise, but the change was not statistically significant. The changes seen in the healthy adolescents were slight compared to those seen in the asthmatic adolescents previously exposed (changes of 23-67%). We conclude that asthmatic adolescents are much more sensitive to the effects of inhaled SO2 than are healthy adolescents.

Adolescent↗

PubMedDate not supplied

Respiratory effects of inhaled sulfuric acid on senior asthmatics and nonasthmatics.

The objective of this study was two-fold: (1) to investigate the response of asthmatic subjects who were 60 to 75 y of age to inhaled sulfuric acid, and (2) to compare that response to findings from healthy subjects in the same age group. Nine subjects who had asthma and eight healthy subjects participated. Each subject was exposed to clean air, an inert ammonium sulfate aerosol, or 70 micrograms/m3 sulfuric acid during a 40-min exposure period composed of 30 min at rest and 10 min of light exercise on a treadmill. The sulfuric acid was delivered twice, one preceded by a lemonade drink to neutralize oral concentrations of ammonia. Exposures were separated by at least 1 wk. Oral ammonia levels and pulmonary function parameters (forced expiratory volume in one second, forced vital capacity, and total respiratory resistance) were measured before and after each exposure. None of the functional parameters in either group showed significant changes. However, total respiratory resistance changes from baseline after sulfuric acid exposure were significantly higher (+16%) in the asthmatic subjects, compared with the healthy subjects (-6%). These data suggest that older subjects are not at increased risk for adverse respiratory effects from inhalation of sulfuric acid by virtue of age alone, and older subjects with asthma are slightly more vulnerable than are their healthy peers.

Adolescent↗

PubMedDate not supplied

Exercise-induced bronchospasm in the XXIII summer Olympic games.

The U.S. Olympic Team demonstrated a significant prevalence of Exercise-Induced Bronchospasm (EIB) among world-class athletes (11.2). Nearly all sports were involved but endurance events seemed to have the highest prevalence of team members with EIB. Resting pulmonary function studies were poor discriminators of athletes affected with EIB. The 67 athletes of the 597 member team were responsible for winning 41 Olympic medals including 15 golds and 21 silvers, clearly demonstrating their ability to compete and succeed in world-class competitive events. These results should send a strong message to young people that they can strive to excel in sports with proper medication and management.

Asthma↗

PubMedDate not supplied

Impact of air pollutants on athletic performance.

Human controlled and observational studies both lead to the conclusion of air pollution adversely affecting athletic performance during training and competition. The dosage of various air pollutants during exercise is much higher due to the marked increase in ventilatory rate and concomitant nasal and oral breathing. This is particularly true for sulfur dioxide which is a highly water-soluble gas and is normally absorbed in the upper airway during nasal breathing. With heavy exercise, oral pharyngeal breathing is the predominant mode of breathing and much larger amounts of sulfur dioxide are delivered to the lower airway resulting in significant impact upon the lower respiratory tract. More recently, several controlled human studies have shown that a combination of exercise and air pollutants such as ozone (O3) or sulfur dioxides (SO2) cause a significant increase in bronchoconstriction and air flow obstruction when compared to the same exposure at rest. In strenuous athletic competition such as the Olympic Games where small increments of time often determine the ultimate success of athletes, the impact of air pollutants and subsequent adverse ventilatory changes can affect athletic performance.

Air Pollutants↗

PubMedDate not supplied

The effect of duration of exposure on sulfuric acid-induced pulmonary function changes in asthmatic adolescent subjects: a dose-response study.

To evaluate the pulmonary effects of varying doses of sulfuric acid, adolescent subjects with asthma were exposed to 35 or 70 micrograms/m3 sulfuric acid for 45 or 90 min. Exposure was carried out during intermittent moderate exercise. The pulmonary functions measured before and after exposure were FEV1, FVC, and total respiratory resistance. The 45 min exposures were associated with larger decreases in FEV1 (-6% or -3%) than the 90 min exposures (-1% or +2%). Analysis of variance of the change in FEV1 among the exposures revealed that the 45 min exposure to 35 micrograms/m3 was significant (p = 0.03). The p value for 45 min exposure to 70 micrograms/m3 was not significant (p = 0.08). Using analysis of variance, neither of the 90 min exposures was associated with a significant decrease in FEV1 compared to air exposure. Also, none of the changes in FVC or RT was significant. When baseline to post-exposure changes were compared for each of the five test atmospheres using paired t tests, both of the 45 min exposures were associated with statistical significance (p < 0.001 for 35 micrograms/m3 and p < 0.005 for 70 micrograms/m3). This baseline to post exposure change was not statistically significant for the 90 min exposures. The reason for the lesser effect on pulmonary function at increased exposure duration is not known; it may be due to changes in either varying deposition patterns or changes in buffering capacity of the cells lining the airways. With respect to individual sensitivities to H2SO4, the data showed a significant consistency across test atmospheres.

Adolescent↗

PubMedDate not supplied

Cetirizine: a unique second-generation antihistamine for treatment of rhinitis and chronic urticaria.

The recent development of selective H1-antagonists that minimally cross the blood-brain barrier has greatly improved the management of allergic rhinitis and chronic urticaria. These new agents have much reduced anticholinergic and sedative side effects, which were the major drawbacks of the classic H1-antihistamines. Cetirizine, a new second-generation H1-antagonist, offers several properties that may further improve the treatment of allergic rhinitis and chronic urticaria. Cetirizine is the only antihistamine known to possess activity against both the histamine-mediated early phase of the allergic response and the late-phase response of immediate hypersensitivity characterized by migration of inflammatory cells to the site of the reaction. Its efficacy has been demonstrated in clinical trials of patients with seasonal rhinitis and urticaria. The most common side effects associated with cetirizine, such as sedation, are similar to those of other second-generation antihistamines. These properties, combined with a once-daily dosage regimen, should help improve patient compliance and optimize antihistamine therapy.

Cetirizine↗