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Biomedical subjects

W E Pierson

Publications and source records attributed to W E Pierson.

At least 19 recordsLinked to original sources
PubMed1992

Respiratory effects of air pollution on allergic disease.

Allergic patients have an increased susceptibility to the adverse effects of both natural and man-made air pollutants. This goes for both indoor and outdoor air pollutants and manifests itself with biochemical, cellular, and pathophysiologic expressions of adverse health effects in allergic individuals. Also occupationally induced allergic diseases will remain very important. This area has been reviewed recently by Cullen et al. Since allergic patients comprise somewhere between 15% and 20% of the population, this increased susceptibility is of crucial importance not only for medical care and research but for legislative and regulatory consideration to protect these vulnerable individuals.

Air Pollutants↗
PubMed1992

Theophylline mitigates the bronchoconstrictor effects of sulfur dioxide in subjects with asthma.

The objective of the study was to investigate the ability of a sustained-release (SR) theophylline tablet (Uniphyl; Purdue Frederick Co., Norwalk, Conn.) to block or mitigate sulfur dioxide (SO2)-induced bronchoconstriction in adult subjects with asthma. Eight subjects participated in a double-blind, crossover study with a 400 mg theophylline tablet or placebo once a day for a week before a 10-minute SO2 challenge. FEV1 and total respiratory resistance (RT) were measured before and after the SO2 challenge and on a different day before and after an air exposure. After exposure to SO2, average values of FEV1 dropped 16% after placebo treatment and 7% after theophylline treatment. The corresponding percentages for RT were a 37% increase after placebo and a 7% increase after theophylline treatment. Analysis of variance demonstrated a significant difference between the SO2-induced decrease in FEV1 and increase in RT after SR theophylline treatment compared with that of placebo treatment. Thus, we conclude that SR theophylline tablets, taken at this concentration for 1 week, mitigate SO2-induced bronchoconstriction.

Adolescent↗
PubMed1992

Response of young asthmatic patients to inhaled sulfuric acid.

The intent of this study was to explore the effects of inhalation of [H+] defined here as acid airborne particles at near ambient concentrations on the pulmonary function of adolescent asthmatic subjects. During rest and exercise, 22 adolescent asthmatic subjects inhaled atmospheres containing either clean air or sulfuric acid particles (H2SO4) through a mouthpiece. The concentration of hydrogen ion at the mouthpiece ([H+]) ranged from 1.18 to 3.59 mumol/m3 (51 to 176 micrograms/m3 of H2SO4). The lower range of [H+] is near the peak values measured during the summer months in the eastern United States and Canada. Pulmonary function and oral ammonia levels were measured before and after exposure in all subjects. Significant group responses to [H+] were seen in FEV1 (p = 0.016) and FVC (p = 0.039) measured 2 to 3 min post-exposure. Also, the slopes of the change in pulmonary function versus [H+] were computed for each subject. The slopes of changes in FEV1 and Vmax50 and Vmax75 versus [H+] were related to the subject's response to a standard exercise treadmill test, specifically to the subject's percentage decrease in FEV1 after exercise challenge. Pulmonary function changes 20 min postexposure did not show a significant group response to [H+] exposure; however, the relationship between percentage FEV1 decrease after exercise and the individual slopes of Vmax50 and Vmax75 persisted for at least 20 min after exposure.

Adolescent↗
PubMed1992

System interactions of air pollutants.

The impact of system interactions and simultaneous or sequential exposure to various air pollutants, both man-made and natural ones, requires greater concern in the interpretation of the total adverse impact of various air pollutants. It is clear that there are highly significant system interactions with exposure to various air pollutants, and these must be considered very carefully in the evaluation of their adverse health effects.

Air Pollutants↗
PubMed1991

Cromolyn versus triamcinolone acetonide for youngsters with moderate asthma.

Although both cromolyn (C) and inhaled corticosteroids are anti-inflammatory therapies for childhood asthma, there are few controlled comparisons of these medications for asthma therapy in children. None were conducted in the United States, and none specifically study triamcinolone acetonide (T) versus C. This 12-week evaluation followed 31 youths, aged 8 to 18 years, with moderate asthma who were assigned to receive C or T according to a prerandomized and blinded code. Patients were instructed to take two inhalations from the study metered-dose inhaler (active T or placebo) and to inhale the contents of one study-provided ampule (C, 20 mg, or placebo) from a compressor-driven home nebulizer three times per day. Patients also used albuterol, two inhalations from a metered-dose inhaler, three times a day (before study medication) and, additionally, if needed. Patients maintained a daily diary, recording extra medication use, adverse experiences, peak flow rates morning and night, and asthma symptom scores. Laboratory assessment of pulmonary function was done at 1, 4, 8, and 12 weeks. Cosyntropin challenge and methacholine bronchoprovocation challenge were performed at the beginning and end of the study. C and T provided similar, adequate asthma control. Symptoms of wheezing, cough, and chest tightness decreased, and daily peak expiratory flow rate increased with both regimens compared to during a 2-week baseline when patients received medication only as needed. There was no significant change in methacholine sensitivity and no change in endocrine function, as measured with fasting plasma control before and after administration of cosyntropin.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗
PubMed1991

Acute pulmonary effects of nitrogen dioxide exposure during exercise in competitive athletes.

The acute pulmonary responses of athletes after short-term exposure to ambient concentrations of NO2 during heavy exercise have been examined. Intercollegiate male athletes were screened for history of cardiac disease, respiratory disease, allergic conditions and extensive exposure to pollutants. After completion of serum IgE level determination, exercise tolerance test and methacholine challenge test with normal results, nine healthy subjects 18 to 23 years of age were exposed to filtered air and to 0.18 and 0.30 ppm NO2 for 30 min on different days while exercising on a treadmill. Pulmonary function parameters were measured before and after each exposure. In this study, no statistically significant changes were observed in FEV1, RT PEFR, and Vmax50% after exposure to 0.18 and 0.30 ppm NO2. For these selected healthy athletes, short-term exposure to ambient NO2 levels during heavy exercise does not affect adversely the pulmonary function.

Adult↗
PubMed1991

Air pollutants and the respiratory system: toxicity and pharmacologic interventions.

Air pollution remains a major aggravation of respiratory symptoms and disease. Sulfur dioxide, ozone, sulfuric acid, particulate matter such as the fine particles from wood smoke, and nitrogen dioxide all produce significant effects when investigated in laboratory or field studies. These effects are decreases in pulmonary function and evidence of inflammation as well as suggestions of increases in chronic respiratory disease. Asthmatic subjects may be the group at greatest risk from air pollutants. Common medications used to treat asthma have varying effects on blocking or mitigating these pollutant-induced effects.

Air Pollutants↗
PubMed1991

Immunologic defects in patients with refractory sinusitis.

Sixty-one patients with chronic sinusitis who were referred for an allergy evaluation were evaluated for immunologic competence including assessment of quantitative serum immunoglobulin levels, IgG subclass levels, and response to pneumococcal and Haemophilus influenzae vaccines. In addition to chronic sinus disease, recurrent otitis media and asthma exacerbation were common problems in this group. Five patients had an elevated age-adjusted IgE level and 22 patients had positive prick tests to one or more environmental inhalants; these findings suggest an allergic component in this subgroup. Twelve additional patients had highly reactive intradermal tests to common environmental allergens, which also may be clinically significant for underlying atopy. Eleven patients had low immunoglobulin levels, 6 had low immunoglobulin levels and vaccine hyporesponsiveness, and 17 had poor vaccine response only. Thus, 34 of 61 patients with refractory sinusitis had abnormal results on immune studies, with depressed IgG3 levels and poor response to pneumococcal antigen 7 being most common. In addition to allergy, immunologic incompetence may be an important etiologic factor in patients with chronic, refractory sinusitis.

Adolescent↗
PubMed1990

Long-term, double-blind comparison of controlled-release albuterol versus sustained-release theophylline in adolescents and adults with asthma.

This parallel-group study compared the safety and efficacy of controlled-release albuterol versus sustained-release theophylline, both administered every 12 hours. One hundred twenty-four adolescent and adult patients with asthma and with chronic reversible obstructive airway disease were studied. All patients qualified with an FEV1 less than or equal to 80% of predicted (not receiving treatment) and greater than or equal to 15% reversibility in FEV1 or greater than or equal to 25% reversibility in FEF25-75% after inhaled isoproterenol. All patients were known to be able to take theophylline without unacceptable adverse effects. Theophylline was titrated for patients to receive, unblinded, theophylline serum concentrations of 10 to 20 micrograms/ml. With subsequent randomization, 62 patients continued to receive theophylline and 62 patients started taking albuterol in the 12-week, double-blind, double-dummy portion of the study. Pulmonary function was measured during a pretreatment visit (unmedicated) and serial assessment was made starting just before the morning dose and continuing for 12 hours after the dose at the end of 1, 6, and 12 weeks of treatment. Both treatment groups exhibited statistically significant increases in FEV1 from the pretreatment visit to all times of observation at weeks 1, 6, and 12. The increases in FEV1 were not significantly different between albuterol and theophylline administration. There was no evidence of tolerance to the bronchodilatory effect during 12 weeks in either treatment group. Only one patient in the study stopped treatment because of an adverse effect. This patient had tremor during albuterol administration. All other adverse events were tolerated or resolved during treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Prior exposure to ozone potentiates subsequent response to sulfur dioxide in adolescent asthmatic subjects.

The objective of this study was to test whether prior exposure to a low concentration of ozone (120 ppb) would condition airways in asthmatic subjects to respond to a subthreshold concentration of sulfur dioxide (100 ppb). Eight male and five female subjects 12 to 18 yr of age participated. They all had allergic asthma and exercise-induced bronchospasm. Subjects were exposed to three test atmosphere sequences during intermittent moderate exercise (a 45-min exposure to one pollutant followed by a 15-min exposure to the second pollutant). The sequences were: air followed by 100 ppb SO2, 120 ppb O3 followed by 120 ppb O3, and 120 ppb O3 followed by 100 ppb SO2. The pulmonary function measurements assessed were FEV1, total respiratory resistance (RT), and maximal flow (Vmax50). Air-SO2 and O3-O3 exposures did not cause significant changes in pulmonary function. On the other hand, exposure to 100 ppb SO2 after a 45-min exposure to 120 ppb O3 caused a significant (8%) decrease in FEV1 (p = 0.046), a significant (19%) increase in RT (p = 0.048), and a significant (15%) decrease in Vmax50 (p = 0.008). It is concluded that prior O3 exposure increased bronchial hyperresponsiveness in these subjects such that they responded to an ordinarily subthreshold concentration of SO2. These data suggest that assessment of pulmonary changes to single pollutant challenges overlooks the interactive effects of common coexisting or sequentially occurring air pollutants.

Adolescent↗
PubMed1990

Effects of albuterol and procaterol on exercise-induced asthma.

Procaterol and albuterol, beta agonists, were studied using a placebo-controlled, repeated exercise challenge design in order to assess their duration of effectiveness in both bronchodilation and in modifying exercise-induced asthma (EIA). Fifty-three subjects aged 12 to 50 years who had at least a 20% drop in FEV1 during a screening exercise tolerance test were entered. Subjects took two inhalations of procaterol (10 micrograms/inhalation), albuterol (90 micrograms/inhalation), or placebo. Thirty minutes later they exercised on a treadmill at a workload sufficient to induce greater than or equal to 80% aerobic O2 consumption for six minutes. Pulmonary function was measured before and serially for 30 minutes after exercise. The same exercise challenge was repeated three, six, and nine hours after drug administration. Both procaterol and albuterol bronchodilated and modified EIA at 30 minutes and three hours, mean drops in FEV1 being 8.2 and 9.7% respectively at 30 minutes and 16.8 and 16.3% at three hours. This was compared with placebo falls of 30% and 26%. At six hours the subjects' response was similar after both procaterol and albuterol, and fewer subjects had a 20% fall in FEV1 than with placebo, although protection afforded by both beta agonists was substantially less than at three hours. Both drugs were tolerated well.

Adolescent↗
PubMed1989

Pulmonary effects of sulfur dioxide exposure and ipratropium bromide pretreatment in adults with nonallergic asthma.

In this study we examined the potential short-term effect of sulfur dioxide (SO2) on total respiratory resistance and forced expiratory volume in patients with nonallergic asthma. A group of nine adult subjects with nonallergic asthma, 55 years of age or older, were exposed to SO2 at 0, 0.5, and 1.0 ppm for 20 minutes at rest followed by 10 minutes during light-moderate exercise. The measures of pulmonary function assessed were FEV1, specific total respiratory resistance (SRT), and maximal expiratory flow rates at 50% (Vmax50) and 75% (Vmax75) of expired vital capacity. Measurements were made before exposure to SO2 (baseline), postresting exposure, postexercising exposure, and at 30 minutes thereafter (recovery). Repeat measure analysis of variance revealed a statistically significant dose-response effect of SO2 inhalation on FEV1 (p = 0.008), SRT (p = 0.033), Vmax50 (p = 0.017), and Vmax75 (p = 0.048). Eight subjects had repeat exposure to SO2 at 1.0 ppm after treatment with either placebo or ipratropium bromide, 60 micrograms by metered-dose inhaler. Inpratropium bromide treatment, compared to placebo treatment, resulted in a statistically significant improvement in all baseline measures of pulmonary function: FEV1 (p = 0.017), SRT (p = 0.027), Vmax50 (p = 0.018), and Vmax75 (p = 0.035). However, this drug did not significantly alter the proportionate change in pulmonary function caused by SO2 inhalation in these subjects. These findings indicate that adults with nonallergic asthma are sensitive to short-term low-level SO2 exposure and that treatment with 60 micrograms of ipratropium bromide causes significant bronchodilation but does not protect, completely, these patients from the effect of SO2 inhalation.

Aged↗
PubMed1989

Effects of inhalation of acidic compounds on pulmonary function in allergic adolescent subjects.

There is concern about the human health effects of inhalation of acid compounds found in urban air pollution. It was the purpose of this study to investigate three of these acid compounds, sulfur dioxide (SO2), sulfuric acid (H2SO4), and nitric acid (HNO3) in a group of allergic adolescent subjects. Subjects were exposed during rest and moderate exercise to 0.7 mumole/m3 (68 micrograms/m3) H2SO4, 4.0 mumole/m3 (0.1 ppm) SO2, or 2.0 mumole/m3 (0.05 ppm) HNO3. Pulmonary functions (FEV1, total respiratory resistance, and maximal flow) were measured before and after exposure. Preliminary analysis based on nine subjects indicates that exposure to 0.7 mumole/m3 H2SO4 alone and in combination with SO2 caused significant changes in pulmonary function, whereas exposure to air or SO2 alone did not. FEV1 decreased an average of 6% after exposure to H2SO4 alone and 4% when the aerosol was combined with SO2. The FEV1 decrease was 2% after both air and SO2 exposures. Total respiratory resistance (RT) increased 15% after the combined H2SO4 exposures, 12% after H2SO4 alone, and 7% after exposure to air. After exposures to HNO3 alone, FEV1 decreased by 4%, and RT increased by 23%. These results are preliminary; final conclusions must wait for completion of the study.

Acid Rain↗
PubMed1989

Terfenadine blockade of exercise-induced bronchospasm.

Terfenadine, in doses of 60, 120, and 180 mg, provided significant bronchodilation for up to four hours after administration. In addition, when the same doses were given four hours prior to exercise, the drug demonstrated significant blockade of exercise-induced bronchospasm at two and five minutes postexercise. These effects on exercise-induced bronchospasm followed a dose-response curve; 180 mg had the most significant effect. All dosing levels, however, produced both bronchodilation and a significant degree of blockade of exercise-induced bronchospasm. No patients were bothered by adverse effects during this single-dose study. Eight of the 11 subjects who completed the study also noted some improvement in their nasal congestion during the testing period when they were on the active drug.

Adolescent↗
PubMed1989

Potential adverse health effects of wood smoke.

The use of wood stoves has increased greatly in the past decade, causing concern in many communities about the health effects of wood smoke. Wood smoke is known to contain such compounds as carbon monoxide, nitrogen oxides, sulfur oxides, aldehydes, polycyclic aromatic hydrocarbons, and fine respirable particulate matter. All of these have been shown to cause deleterious physiologic responses in laboratory studies in humans. Some compounds found in wood smoke--benzo[a]pyrene and formaldehyde--are possible human carcinogens. Fine particulate matter has been associated with decreased pulmonary function in children and with increased chronic lung disease in Nepal, where exposure to very high amounts of wood smoke occurs in residences. Wood smoke fumes, taken from both outdoor and indoor samples, have shown mutagenic activity in short-term bioassay tests. Because of the potential health effects of wood smoke, exposure to this source of air pollution should be minimal.

Humans↗
PubMed1989

Studies of neutrophil chemotactic factor of anaphylaxis in metabisulfite sensitivity.

The mechanism(s) of adverse reactions to sulfites remains unclear. To determine whether mast cell degranulation is involved in sulfite sensitivity, we performed single-blind, placebo-controlled oral aqueous challenges with potassium metabisulfite in 13 patients with histories suggestive of sulfite sensitivity. Ten patients were also skin tested with potassium metabisulfite at 10 mg/mL and all had negative reactions. Serum samples were obtained from all the patients before the challenge and for 180 minutes after the challenge. The samples were tested for the presence of neutrophil chemotactic factor of anaphylaxis, using both a 51chromium microchamber chemotaxis assay and a leukocyte polarization technique. Six of 13 patients had positive challenges as defined by a fall equal to or greater than 20% in their forced expiratory volume in one second. No significant increase in neutrophil chemotactic factor activity was detected in the postchallenge serum samples from patients who experienced positive or negative challenges. We conclude that sensitivity to aqueous metabisulfite is not associated with mast cell degranulation in metabisulfite skin test-negative patients.

Adult↗