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Biomedical subjects

A F Barker

Publications and source records attributed to A F Barker.

At least 19 recordsLinked to original sources
PubMed1998

Treatment of idiopathic bronchiectasis with aerosolized recombinant human DNase I. rhDNase Study Group.

STUDY OBJECTIVE: To study the safety and efficacy of aerosolized recombinant human DNase I in the treatment of idiopathic bronchiectasis. DESIGN: Double-blind, randomized, placebo-controlled, multicenter study. POPULATIONS: Three hundred forty-nine adult outpatients in stable condition with idiopathic bronchiectasis from 23 centers in North America, Great Britain, and Ireland. INTERVENTIONS AND MEASUREMENTS: Study patients received aerosolized rhDNase or placebo twice daily for 24 weeks. Primary end points were incidence of pulmonary exacerbations and mean percent change in FEV1 from baseline over the treatment period. RESULTS: Pulmonary exacerbations were more frequent and FEV1 decline was greater in patients who received rhDNase compared with placebo during this 24-week trial. CONCLUSIONS: rhDNase was ineffective and potentially harmful in this group of adult outpatients in stable condition with idiopathic bronchiectasis. This contrasts with previously published results that demonstrated efficacy of rhDNase in patients with cystic fibrosis bronchiectasis.

Administration, Inhalation↗
PubMed1997

Pharmacokinetic study of alpha1-antitrypsin infusion in alpha1-antitrypsin deficiency.

OBJECTIVES: To ascertain how long 120 mg/kg alpha1-antitrypsin concentrate (alpha1-AT-C), administered I.V. every 2 weeks, can maintain alpha1-antitrypsin (alpha1-AT) serum levels above 70 to 80 mg/dL. Secondary objectives were to summarize the nature, severity, and relationship of a plasma-derived alpha1-AT-C infusion to any side effects. METHODS: This was an open-label uncontrolled pharmacokinetic study. Alpha1-AT-C was administered I.V. every 2 weeks for 10 infusions in 23 patients with PIZ alpha1-AT deficiency. Serum alpha1-AT levels and neutralizing elastase activity were measured preinfusion, postinfusion, and at nadir. During two infusion periods, daily serum alpha1-AT and neutralizing elastase activities were measured on the seventh to 14th days. Five patients received BAL assays for alpha1-AT and neutralizing elastase activity. Adverse events were recorded in a patient diary and by a nurse at each infusion visit. RESULTS: The 120-mg/kg dose of alpha1-AT-C could not maintain nadir serum protective levels above 70 or 80 mg/dL for the entire 14-day dosing interval in most patients. None of the patients had alpha1-AT levels above 80 mg/dL for all 14 days. The serum alpha1-AT and neutralizing elastase levels correlated suggesting functional activity. The BAL alpha1-AT and neutralizing elastase activities were low and did not correlate with serum levels. CONCLUSION: Alpha1-AT-C at 120 mg/kg administered every 2 weeks did not maintain nadir serum alpha1-AT levels above 70 to 80 mg/dL for a 14-day dosing interval. Higher doses every 2 weeks or decreased interval between infusions may be required.

Adult↗
PubMed1996

Clinical features of individuals with PI*SZ phenotype of alpha 1-antitrypsin deficiency. alpha 1-Antitrypsin Deficiency Registry Study Group.

This report describes the clinical characteristics of a group of 59 individuals with the PI*SZ phenotype and alpha 1-antitrypsin (alpha 1-AT) deficiency, identified during recruitment of a registry for subjects with severe alpha 1-antitrypsin deficiency. Currently, 1,129 individuals with levels of alpha 1-AT of 11 microM or below have been enrolled in this registry. Individuals with the SZ phenotype whose alpha 1-AT levels are at or below 11 microM will be followed in the registry; those whose levels exceeded 11 microM had baseline studies and are included in this report. Baseline pulmonary function tests included spirometry before and after an inhaled bronchodilator, diffusing capacity for carbon monoxide (DLCO), and chest roentgenograms. Among nonsmokers, subjects with the SZ phenotype demonstrated airflow obstruction less frequently than those with with the ZZ phenotype. Among ex- and current smokers, the frequency and severity of airflow obstruction was similar between SZ and ZZ subjects. Individuals with the SZ phenotype reported respiratory symptoms less frequently than did ZZ subjects. Overall, airflow obstruction was less common and milder among PI*SZ than PI*ZZ subjects. Cigarette smoking correlated more strongly with airflow obstruction among PI*SZ than PI*ZZ subjects. These observations indicate that in smokers, the PI*SZ phenotype confers a significant risk of the development of chronic obstructive pulmonary disease (COPD). Of itself, except in rare instances in nonsmoking individuals, the PI*SZ phenotype may confer little or no added risk of developing COPD.

Adult↗
PubMed1995

Bronchiectasis.

Bronchiectasis is a chronic suppurative respiratory disease of declining prevalence but continuing morbidity due to recurrent respiratory infections and bronchial bleeding. Literature was reviewed through a Medline search for the past 4 years. Almost all reports are retrospective case summaries. This review focuses on the clinical assessment, stressing the recognition of an impaired host and infectious contributions. High-resolution computed tomography has supplanted bronchography as a key diagnostic tool. Treatment includes prompt attention to acute bacterial infections, aerosol bronchodilators and inflammatory agents, and bronchial hygiene. The role of surgery has declined at least by the number of literature reports. Except for cures for local bronchiectasis, surgical resection is now used to palliate disease activity by removing the most affected segments and lobes.

Bronchiectasis↗
PubMed1994

Replacement therapy for hereditary alpha1-antitrypsin deficiency. A program for long-term administration.

This retrospective chart review describes the efficacy and safety of long-term administration of intravenous alpha1-antitrypsin (AAT) in 14 patients with hereditary AAT deficiency and COPD. During the 12- to 48-month observation period, 12 to 14 patients had stabilization of functional status; 4 patients had reductions in hospitalizations. Thirteen of 14 patients had no decline in pulmonary function. Three patients had self-limited adverse reactions to the AAT with one patient requiring a brief hospitalization.

Adult↗
PubMed1991

Airway responsiveness in atopic dermatitis.

Twelve of 123 patients with atopic dermatitis (AD) were screened by questionnaire and spirometry for the absence of smoking, hay fever, and respiratory disorders. Seven of these 12 patients had a positive methacholine challenge test. None of eight patients with another skin disorder, psoriasis, screened in a similar fashion, had a positive methacholine challenge. We conclude that hyperresponsive airways are a frequent finding in patients with AD and that similar mechanisms may account for the cutaneous physiologic and pharmacologic abnormalities that have been observed in AD.

Adult↗
PubMed1989

Strategies in managing asthma.

The management of adult asthma involves a concerted effort to identify and remove or mollify inciting or triggering stimuli such as respiratory tract infections, gastric reflux, aspirin, beta-antagonists, and environmental agents; educate patients, using written treatment plans and pulmonary function monitoring; and properly use the antiasthmatic medications including beta-agonists, theophylline, anticholinergics, and corticosteroids, with an emphasis on aerosol delivery and the use of corticosteroids during exacerbations. This strategy is summarized with suggestions on therapy in emergency departments, during the transition from hospital to ambulatory care, before exercise, and during pregnancy.

Asthma↗
PubMed1989

Components of a smoke-free hospital program.

Hospitals have the responsibility to provide leadership in the area of cigarette-smoking cessation and indoor-smoking elimination. A multidisciplinary committee of the Oregon Health Sciences University, Portland, planned and initiated a smoke-free hospital and clinic facility in 1987. The key planning steps for the patient and visitor ban included involvement of many representatives of the hospital staff, 2 months lead time for the ban, personal interviews with all inpatient smokers on the eve of the ban, and distribution of survival kits. Employees were offered free smoking cessation classes, gum with instructions in use, and a protected outdoor smoking area. The ban has been well accepted by patients and visitors. A questionnaire survey of employees at 6 months has indicated a modest reduction in personal cigarette smoking.

Employee Incentive Plans↗
PubMed1987

Humoral immunity in bronchiectasis.

Bronchiectasis occurs in patients with immunodeficiency and fungal hypersensitivity disorders. To assess the prevalence of abnormal humoral immune parameters in bronchiectasis, a retrospective study was carried out on sera from 30 patients. Studies included immunoglobulin quantitation and specific antibody to fungal species. Eleven patients were found to have immunodeficiency (nine with panhypoglobulinemia and two with selective IgM deficiency). Six patients had elevations of serum IgA and four patients had elevations of serum IgE. Six patients had elevated total antibody to Aspergillus or Candida species and six had precipitin bands to one or more fungal antigens. This study indicates that immunodeficiency is prevalent and plays a causative role in some patients with bronchiectasis. Hypersensitivity reactions to Aspergillus, Candida, and other ubiquitous environmental fungi may also play an etiopathogenic role in this disease (bronchiectasis, humoral immunity, immunodeficiency).

Adult↗
PubMed1986

Cardiac arrhythmias during the combined use of beta-adrenergic agonist drugs and theophylline.

We studied 15 nonsmoking, clinically stable asthmatic subjects aged 27 to 39 years to evaluate the potential cardiotoxic effects of combined use of a beta-adrenergic agonist drug and theophylline in the treatment of asthma. Subjects underwent a one-week washout period followed by two one-week periods of study receiving either oral terbutaline or sustained-release theophylline during week 1 and both drugs during week 2. Thirty-six-hour Holter monitoring was performed at the end of each period of study. No significant increase in the total number of ventricular premature beats was noted, although the average heart rate increased significantly between each period of study. Although not statistically significant, the number of individuals with multiform or complete and repetitive ventricular premature beats increased from one at baseline to three during each period of study, including one subject with ventricular tachycardia on combined therapy. These data suggest that combined therapy with theophylline and a beta-adrenergic agonist in young, otherwise healthy asthmatic subjects does not lead to an increase in the total number of ectopic beats but may increase the degree of complexity of ventricular premature beats.

Adrenergic beta-Agonists↗
PubMed1985

Catamenial hemoptysis. New methods of diagnosis and therapy.

Bronchopulmonary endometriosis is a rare cause of hemoptysis. We describe a woman with catamenial hemoptysis which was localized with chest CAT scanning and treated successfully with danazol. The proposed pathogenesis and manifestations of thoracic endometriosis are reviewed, and the use of new diagnostic and therapeutic modalities in its management are discussed.

Adult↗
PubMed1984

Pulmonary arteriovenous fistulas occluded by percutaneous introduction of coil springs.

Between July 1980 and July 1983, we occluded 30 pulmonary arteriovenous fistulas (PAVFs) in four patients by percutaneous placement of coil springs. All patients had significant right-to-left shunts and hypoxemia. One presented with recurrent cerebral abscesses following bilateral thoracotomy and lobectomy. The technique requires advancement of the catheter superselectively into the feeding artery just proximal to the fistula. Occlusion at this site preserves the maximum amount of functioning pulmonary parenchyma. Frequently more than one coil spring is required for occlusion. In our experience, the coil spring is a safe, effective, economical vaso-occlusive device for management of PAVFs.

Adult↗