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Biomedical subjects

R W Weber

Publications and source records attributed to R W Weber.

At least 19 recordsLinked to original sources
PubMed1992

Use of standardized and conventional allergen extracts in prick skin testing.

This study examined whether commercially available conventional and standardized allergen extracts differ enough in potency to affect routine prick skin test results. Extracts of white oak, timothy, Bermuda, Russian thistle, short ragweed, sagebrush, Alternaria, and cat dander were examined in allergic patients and in nonatopic subjects with no personal or family history of asthma, rhinitis, or eczema. Conventional nonstandardized extracts (1:10 or 1:20 wt/vol) from two sources were compared with three concentrations (100,000, 10,000, and 1000 AU/ml) of a single standardized extract. Preparations were compared in the allergic patients with computerized planimetry, and in all patients and subjects with a conventional skin test grading system. Skin test area for the conventional extracts generally fell between the 10,000 and 100,000 AU/ml concentrations of the standardized extract. Skin test reactivity to at least one allergen extract occurred in 31% of the nonatopic subjects; there was no difference between the number of 3+ and 4+ reactions for conventional and standardized extracts. Results indicate that standardized and conventional extracts are frequently similar, but are not directly interchangeable.

Adolescent↗
PubMed1992

Aerobiology of the Colorado Rockies: pollen count comparisons between Vail and Denver, Colorado.

Pollen patterns were compared between Vail, CO (8,200 feet elevation), Aspen, CO (7,900 feet) and Denver, CO (5,280 feet) from 1984 through 1988. Counts were obtained at all sites with a volumetric intermittent cycling rotating impaction sampler. Aspen and Denver were compared in 1984, and Vail and Denver from 1985 through 1988. While counts were generally lower in the mountain sites than Denver, certain pollens, especially trees, were quite high. Ragweed was essentially absent from Aspen and Vail, and chenopod-amaranth counts were very low. Cedar, pine, and aspen frequently pollinated despite active snowfall.

Air Pollution↗
PubMed1991

Methotrexate in the treatment of steroid-dependent asthma.

A double-blind, placebo-controlled, crossover study was designed to compare steroid requirements between placebo and methotrexate (MTX) treatment in subjects with corticosteroid-requiring asthma. Subjects began with a steroid taper and then were randomized to a 3-month trial of drug or placebo therapy. Subjects received 15 mg of MTX a week or identical placebo. A 1-month washout period was completed before the crossover trial. Symptom scores, peak flow rates, spirometry, and beta-agonist frequency were closely monitored. Ten subjects completed the study. The average dose of prednisone during the placebo-treatment period was 11.97 mg/day compared to 8.37 mg/day while subjects were taking MTX. This was a 30% reduction in daily steroid requirement (p less than 0.01). Symptom scores and spirometry did not differ between the crossover trials, and overall clinical status was not altered. Complications from MTX were mild and included anorexia, alopecia, and stomatitis. All complications resolved with dose reduction or when MTX was stopped at the end of the study. No subjects withdrew from the study because of MTX complications. Low-dose MTX significantly reduced the steroid requirement in this group of subjects with steroid-dependent asthma. This reduction in steroid requirement was obtained without altering clinical status and without significant complication.

Adolescent↗
PubMed1991

Occupational asthma and rhinoconjunctivitis from inhalation of crystalline bovine serum albumin powder.

A 24-year-old white female laboratory technician developed recurrent rhinoconjunctivitis and wheezing immediately following repeated exposure to purified lyophilized bovine serum albumin (BSA). Prick and titrated intradermal skin tests revealed strongly positive results in the patient and negative results in normal controls. A titrated double-blind, placebo-controlled bronchial inhalation challenge with an aqueous BSA solution was positive at 10 mg/mL. Use of an albuterol metered dose inhaler and avoidance of laboratory exposure to BSA have resulted in resolution of symptoms. These results are consistent with an IgE-mediated mechanism, and this case represents the first reported instance of occupational asthma and rhinoconjunctivitis to inhaled BSA powder.

Administration, Inhalation↗
PubMed1990

Chronic urticaria exacerbated by the antioxidant food preservatives, butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT).

Two patients with chronic idiopathic urticaria in whom remissions were achieved with dye- and preservative-elimination diet had exacerbations of their urticaria when they were challenged under double-blind, placebo-controlled conditions with butylated hydroxyanisole and butylated hydroxytoluene. After elimination of butylated hydroxyanisole and butylated hydroxytoluene from their diets, there was marked abatement of the frequency, severity, and duration of their urticaria. These antioxidants appear capable of aggravating symptoms in certain patients with chronic urticaria.

Acetaminophen↗
PubMed1989

Hypereosinophilia, neurologic, and gastrointestinal symptoms after bee-pollen ingestion.

A patient developed hypereosinophilia (13,440 cells per cubic millimeter) 6 weeks after beginning the ingestion of bee pollen. Symptoms included generalized malaise, headache, nausea, abdominal pain diarrhea, generalized pruritus, and decreased memory. Evaluation revealed no other known cause for the patient's hypereosinophilia, which resolved after bee-pollen ingestion was stopped. The product contained a mixture of entomophilous and anemophilous pollens to which the patient was skin test positive. An open challenge with the bee pollen later reproduced the presenting symptoms with a concomitant rise of the eosinophil count from 207 to 890 cells per cubic millimeter. The patient has since remained well avoiding bee pollen. This study strongly suggests that hypereosinophilia with attendant pathophysiologic disturbances may be an adverse reaction to bee-pollen ingestion in atopic individuals.

Adult↗
PubMed1989

Evaluation of nasal patency by fiberoptic rhinoscopy.

A novel method of assessing anterior nasal patency by flexible fiberoptic rhinoscopy was evaluated in two centers by comparison with active anterior rhinomanometry. Rhinoscopy and rhinomanometry were performed 20 times on each of 14 subjects during 14 to 26 minutes. The procedure was videotaped, and nasal airway area was measured from a video monitor. The mean coefficients of variation for rhinoscopy and rhinomanometry were 14% and 19%, respectively. Another investigator examined five subjects by rhinoscopy 30 times in 15 minutes; the mean coefficient of variation was 9%. These means were not significantly different. Rhinoscopy and rhinomanometry were performed at 30-minute intervals for a 6-hour period in 13 subjects. Three investigators independently evaluated results for changes in nasal function characteristic of the nasal cycle. Rhinoscopy detected the nasal cycle in an average of 72% of subjects and rhinomanometry in 49%. Both methods detected the response to topically applied oxymetazoline and methacholine. Results indicate that, whereas the two procedures evaluate different aspects of nasal function, their precision is similar. Rhinoscopy additionally permits evaluation of nasal mucosal changes occurring from disease or treatment.

Airway Resistance↗
PubMed1989

Comparison of PEFR and FEV1 in patients with varying degrees of airway obstruction. Effect of modest altitude.

Measurements of FEV1 and PEFR performed on a Jones Pulmonor Spirometer (JPF) were compared with PEFR obtained with a mini-Wright peak flow meter (WPF) in 102 patients. Data were converted to percent predicted. Standard deviations of triplicate measurements were: FEV1, 3.01 percent; JPF, 7.22 percent; and WPF, 5.12 percent. Correlation of best of three measurements was FEV1-JPF r = .758; FEV1-WPF r = .744; and JPF-WPF r = .846. The mean percent predicted of the best of three values of FEV1 was 74.8 percent, JPF 91.4 percent, and WPF 94 percent. These higher values for percent predicted PEFR were obtained throughout the range of FEV1 values. Studies on nine normal volunteers in an atmospheric chamber suggested that higher altitudes may account for higher PEFR values. We conclude that PEFR, measured by either waterless spirometer or mini-Wright peak flow meter, has greater intrasubject variability than FEV1, and it tends to underestimate the degree of pulmonary impairment.

Adolescent↗
PubMed1988

The development of subsensitivity to atropine methylnitrate. A double-blind, placebo-controlled crossover study.

This is a double-blind, placebo-controlled crossover study designed to assess the effectiveness of nebulized atropine methylnitrate (AMN) with chronic use. We studied 22 patients with asthma, 10 receiving theophylline and inhaled beta-agonists and 12 who were receiving corticosteroids as well. All had demonstrated at least a 15% change in FEV1 either spontaneously or after bronchodilator. Bronchodilator effect was measured serially for 4 h after inhalation of the initial dose and again after 2 wk of four-times-daily use. Significant bronchodilator effect was seen initially with AMN when compared to placebo (p less than 0.01). After 2 wk of use, the bronchodilator effect of AMN was significantly diminished as compared to the initial effect (p less than 0.01) but was still better than placebo (p less than 0.05). Subsensitivity did develop to varying degrees in the patients, but we were unable to identify any clinical parameters that would allow prediction of subsequent subsensitivity. We conclude that the development of subsensitivity to AMN occurs in certain patients with chronic administration but does not reflect a total loss of bronchodilator effect.

Adult↗
PubMed1987

Allergens.

The environment contains a huge array of allergens, primarily proteins or glycoproteins, to which the atopic individual may become sensitized. In situations of high exposure and highly reactive substances, even nonatopic individuals may develop allergic antibodies. The individual's response depends on the underlying immune responsiveness, the dosage, frequency, route, and possibly the chemical nature of the allergen. Most allergenic sources contain multiple allergenic determinants, as demonstrated by characterization of pollen and mold extracts. Major allergens are acidic proteins with weights in the 20,000 to 40,000 dalton range, and pIs in the 4 to 6 range. Minor allergens may be larger or smaller and either acidic or basic. These conclusions are based on the isolation of a relatively small number of allergens. Cross-reactivity data, especially with the pollens, are useful in the rational formulation of immunotherapy extracts. Considering the wealth of allergenic pollens, information available to date is very scanty. Data on molds, epidermals, and mites are even more preliminary or conflicting. As further research proceeds on purifying and characterizing allergens, a number of these questions and conflicts will be resolved.

Bronchial Provocation Tests↗
PubMed1986

Addition of terbutaline to optimal theophylline therapy. Double blind crossover study in asthmatic patients.

The efficacy and side effects of oral or inhaled terbutaline were examined in 13 mild-to-moderate asthmatic patients (ages 12 to 71 years) on maintenance theophylline (levels 10 to 25 micrograms/ml). In a crossover design, each patient received for two weeks oral terbutaline, 5 mg qid, inhaled terbutaline, 400 micrograms qid, or identical placebo tablets or metered-dose inhalers. Prior to each double-blind period, terbutaline was given for two weeks to ensure development of beta-adrenergic subsensitivity. Home-monitored peak flows and need for supplementary bronchodilators were significantly improved with both oral and inhaled terbutaline, but only the inhaled drug significantly decreased symptoms. Long-term terbutaline, either oral or inhaled, added to maintenance theophylline improved the patients' pulmonary function. The inhaled drug also improved the patients' clinical status as reflected by asthma symptom scores and need for extra bronchodilator. Combining terbutaline with theophylline did not produce evidence of cardiotoxicity.

Administration, Intranasal↗