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Biomedical subjects

G G Shapiro

Publications and source records attributed to G G Shapiro.

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

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

Methacholine challenge--relevance for the allergic athlete.

Methacholine challenge for diagnosing hyperreactive airways has been valuable in both research and clinical care settings. There are two methods of challenge that are commonly used. With the dosimeter method, five breaths of sequential concentrations of methacholine are inhaled with use of a solenoid valve timing device to standardize the quantity of inhaled methacholine solution. Pulmonary function is assessed after each concentration is inhaled. With the continuous breathing method, each concentration of methacholine is inhaled by tidal volume breathing for 2 min. Pulmonary function is assessed after each concentration. With both methods, a fall in FEV1 of 20% after inhalation of methacholine is diagnostic of hyperreactive airways. Several evaluations demonstrate that pharmacologic bronchial provocation with methacholine is more sensitive than exercise challenge for making the diagnosis of hyperreactive airways. If the allergic athlete complains of exercise-related symptoms, such as cough, dyspnea, or chest pain, and an exercise tolerance test fails to reproduce these symptoms, a methacholine challenge should be performed before the possibility of exercise-induced asthma is dismissed. If the allergic athlete has symptoms of cough or dyspnea that are unrelated to exercise, methacholine challenge is the most sensitive method to evaluate airways hyperreactivity indicative of asthma.

Bronchial Provocation Tests↗
PubMed1984

Otitis media with effusion in childhood.

OM and OME are common disorders of childhood. Middle ear disease is related to anatomic abnormalities, prior episodes of AOM, chronic rhinitis, allergy, age, sex, race, season, perinatal factors, viral infections, and irritant exposure. ET dysfunction plays an important role in OME, as does the presence of bacteria or bacterial products in the middle ear. Viral infection, nasal allergy, previous episodes of OM and primary mucosal disease all may contribute to this chronic disorder. Diagnostic evaluation involves an appropriate personal and environmental history, a physical examination, pneumatic otoscopy, tympanometry, pure tone audiometry, and (if indicated) allergic and immunologic evaluation. Treatment may include environmental control, antibiotic therapy, decongestants and/or antihistamines, topical corticosteroids, and possibly immunization or allergic immunotherapy (hyposensitization). In order to facilitate strategies to prevent acute and recurrent OM as well as chronic effusion, further knowledge regarding the etiology, pathogenesis, and risk factors is essential. Well designed, controlled studies are imperative to provide further understanding and more effective treatment of this common, chronic and often very frustrating medical problem.

Administration, Oral↗
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↗
PubMed1983

Risk factors for persistent middle-ear effusions. Otitis media, catarrh, cigarette smoke exposure, and atopy.

To ascertain risk factors for persistent middle-ear effusions (PMEE), we interviewed the parents of two groups of children. The first consisted of 76 children with PMEE who were admitted to the hospital for tympanostomy-tube insertion. The second, a control group, consisted of 76 children admitted for other types of surgery, who were matched for age, sex, season, and surgical ward. Nearly all (97%) of the children admitted for insertion of tympanostomy tubes had one or more episodes of suppurative otitis media. Only 59% of the control children had previous ear infections. Frequent ear infections sharply increased the risk for persistent effusions. Catarrh, household cigarette smoke exposure, and atopy also occurred more frequently in children with PMEE. The risk for middle-ear effusions was greatest when these three factors were all present. The avoidance of daily exposure to domestic tobacco smoke and, if atopic, of specific allergens should be included in the medical treatment of children with PMEE.

Age Factors↗
PubMed1983

Dyphylline versus theophylline: a double-blind comparative evaluation.

This study was a randomized double-blind evaluation of three doses of dyphylline, theophylline, and placebo for blocking exercise-induced bronchospasm (EIB). Twenty patients aged 12 to 17 years took one of the following on five separate days prior to an exercise challenge: 10, 15, or 20 mg/kg dyphylline; 6 mg/kg anhydrous theophylline; or placebo. Linear relationships were found between the log of dyphylline doses and per cent changes from baseline for PEFR, FEV1 and FEF25-75%. The 15 and 20 mg/kg doses differed significantly from placebo in preventing declines in PEFR, FEV1, and FEF25-75%. While significant, these changes were one half to one third those found with 6 mg/kg theophylline. Tremor was twice as common with theophylline. While dyphylline has therapeutic effectiveness compared to placebo for blocking EIB, its benefit is small. Further evaluations are needed to elucidate optimal dosaging for maximal effectiveness.

Adolescent↗