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Biomedical subjects

Allan Becker

Publications and source records attributed to Allan Becker.

12 recordsLinked to original sources
PubMed2006

Primary prevention of childhood asthma and allergic disorders.

PURPOSE OF REVIEW: The prevalence of asthma and allergic disorders in childhood is increasing in many parts of the world. This review focuses on recent findings with regard to environmental risk factors and their manipulation in the primary prevention of these diseases in childhood. RECENT FINDINGS: Recent studies have failed to resolve the controversy on the subject of exposure to indoor aeroallergens and the risk of sensitization and asthma in childhood. Bronchiolitis due to respiratory syncytial virus in infancy is associated with a significant increase in risk of asthma, but not atopy. In the prevention of these diseases, the effects of breastfeeding are controversial, with studies showing a protective effect in children without allergic predisposition, but other studies showing no effect or even the potential for an increased asthma risk. A significant reduction in the prevalence of doctor-diagnosed asthma at 7 years was found in a randomized controlled multifaceted (reduction of inhaled and ingested allergens) intervention study of high-risk infants. Other intervention measures, such as an education program on how to reduce exposure, the use of probiotics, and immunization against infections, all showed some protective effects. SUMMARY: More research is required, especially with regard to longer periods of follow-up for all current intervention studies aimed at reducing exposure, the onset and duration of intervention, and other novel intervention measures in the primary prevention of asthma and allergic diseases in childhood.

Animals↗
PubMed2006

Implementing practice guidelines: a workshop on guidelines dissemination and implementation with a focus on asthma and COPD.

The present supplement summarizes the proceedings of the symposium "Implementing practice guidelines: A workshop on guidelines dissemination and implementation with a focus on asthma and COPD", which took place in Quebec City, Quebec, from April 14 to 16, 2005. This international symposium was a joint initiative of the Laval University Office of Continuing Medical Education (Bureau de la Formation Médicale Continue), the Canadian Thoracic Society and the Canadian Network for Asthma Care, and was supported by many other organizations and by industrial partners. The objectives of this meeting were to examine the optimal implementation of practice guidelines, review current initiatives for the implementation of asthma and chronic obstructive pulmonary disease (COPD) guidelines in Canada and in the rest of the world, and develop an optimal strategy for future guideline implementation. An impressive group of scientists, physicians and other health care providers, as well as policy makers and representatives of patients' associations, the pharmaceutical industry, research and health networks, and communications specialists, conveyed their perspectives on how to achieve these goals. This important event provided a unique opportunity for all participants to discuss key issues in improving the care of patients with asthma and COPD. These two diseases are responsible for an enormous human and socioeconomic burden around the world. Many reports have indicated that current evidence-based guidelines are underused by physicians and others, and that there are many barriers to an effective translation of recommendations into day-to-day care. There is therefore a need to develop more effective ways to communicate key information to both caregivers and patients, and to promote appropriate health behaviours. This symposium contributed to the initiation of what could become the "Canadian Asthma and COPD Campaign", aimed at improving care and, hence, the quality of life of those suffering from these diseases. It is hoped that this event will be followed by other meetings that focus on how to improve the transfer of key recommendations from evidence-based guidelines into current care, and how to stimulate research to accomplish this.

Asthma↗
PubMed2005

Canadian Pediatric Asthma Consensus guidelines, 2003 (updated to December 2004): introduction.

BACKGROUND: Although guidelines for the diagnosis and management of asthma have been published over the last 15 years, there has been little focus on issues relating to asthma in childhood. Since the last revision of the 1999 Canadian asthma consensus report, important new studies, particularly in children, have highlighted the need to incorporate this new information into asthma guidelines. OBJECTIVES: To review the literature on asthma published between January 2000 and June 2003 and to evaluate the influence of new evidence on the recommendations made in the Canadian Asthma Consensus Report, 1999 and its 2001 update with a major focus on pediatric issues. METHODS: Diagnosis of asthma in young children, prevention strategies, pharmacotherapy, inhalation devices, immunotherapy and asthma education were selected for review by small expert resource groups. In June 2003, the reviews were discussed at a meeting under the auspices of the Canadian Network For Asthma Care and the Canadian Thoracic Society. Data published up to December 2004 were subsequently reviewed by the individual expert resource groups. RESULTS: This report evaluates early life prevention strategies and focuses on treatment of asthma in children. Emphasis is placed on the importance of an early diagnosis and prevention therapy, the benefits of additional therapy and the essential role of asthma education. CONCLUSION: We generally support previous recommendations and focus on new issues, particularly those relevant to children and their families. This guide for asthma management is based on the best available published data and the opinion of health care professionals including asthma experts and educators.

Administration, Inhalation↗
PubMed2005

The Canadian Childhood Asthma Primary Prevention Study: outcomes at 7 years of age.

BACKGROUND: Avoidance of any one of the individual risk factors associated with childhood asthma has not been successful in preventing its development. OBJECTIVE: The purpose of this study is to determine the effectiveness of a multifaceted intervention program for the primary prevention of asthma in high-risk infants at 7 years of age. METHODS: Five hundred forty-five high-risk infants with an immediate family history of asthma and allergies were prospectively randomized into intervention or control groups prenatally. Intervention measures introduced before birth and during the first year of life included avoidance of house dust, pets, and environmental tobacco smoke and encouragement of breast-feeding with delayed introduction of solid foods. Assessment of outcomes at 7 years consisted of examination by pediatric allergists, methacholine inhalation tests, and allergy skin tests. RESULTS: At 7 years, 469 of the 545 children were contacted, and 380 returned for further assessment. The prevalence of pediatric allergist-diagnosed asthma was significantly lower in the intervention group than in the control group (14.9% vs 23.0%; adjusted risk ratio, 0.44; 95% CI, 0.25-0.79). The prevalence of allergic rhinitis, atopic dermatitis, atopy (defined as positive skin test reactions to any common allergen), and bronchial hyperresponsiveness (defined as the provocative concentration of methacholine that induced a 20% decrease in FEV 1 from a postsaline value of less than 7.8 mg/mL) were not significantly different between the 2 groups. The prevalence of asthma (defined as wheeze without colds and the presence of bronchial hyperresponsiveness) was also significantly lower in the intervention group compared with the control group (12.9% vs 25.0%; adjusted risk ratio, 0.39; 95% CI, 0.22-0.71). CONCLUSION: The multifaceted intervention program was effective in reducing the prevalence of asthma in high-risk children at 7 years of age.

Asthma↗
PubMed2004

The Canadian asthma primary prevention study: outcomes at 2 years of age.

BACKGROUND: Avoidance of individual risk factors have not been successful in preventing the development of asthma. OBJECTIVE: We sought to determine the effectiveness of a multifaceted intervention program in primary prevention of asthma in high-risk infants. METHODS: We identified 545 high-risk infants on the basis of an immediate family history of asthma. Families were randomized into intervention or control groups. Intervention measures included avoidance of house dust mite, pet allergen, and environmental tobacco smoke. Breast-feeding was encouraged with formula supplementation if necessary, and introduction of solid foods was delayed. RESULTS: At 2 years of age, 19.5% of the children had asthma, and 14.7% had atopy (positive skin test response to one or more common allergens). Significantly fewer children had asthma in the intervention group compared with in the control group (16.3% vs 23.0%), with 60% less persistent asthma at 2 years. There was a 90% reduction for recurrent wheeze in the intervention group compared with that seen in the control group. Exposure to maternal environmental tobacco smoke during pregnancy or the first year was a risk factor for asthma at 2 years of age. A positive skin test response, particularly to food, at 12 months predicted asthma at 2 years. There was no significant difference for atopy between the intervention and control groups, but daycare reduced atopy at 2 years. CONCLUSION: This multifaceted intervention program during a window of opportunity in the first year of life was effective in preventing asthma in high-risk children at 2 years of age. Future studies with this cohort at school age are important.

Allergens↗
PubMed2004

Montelukast in asthmatic patients 6 years-14 years old with an FEV1 > 75%.

OBJECTIVES: Montelukast is a potent leukotriene receptor antagonist effective for treating asthma symptoms in adult and pediatric patients. The purpose of this analysis was to assess the clinical efficacy of montelukast, a potent leukotriene-receptor antagonist, in a subgroup analysis of patients aged 6 years-14 years with milder asthma, defined as a percentage predicted forced expiratory volume in 1 s (FEV1) > 75% using data from a clinical trial of pediatric patients with a broad range of asthma severities. RESEARCH DESIGN AND METHODS: The original previously published clinical trial was an 8-week multi-center, randomized, double-blind, parallel-group study conducted in 47 centers in the United States and Canada. The study compared the efficacy of once daily montelukast 5 mg to placebo in patients 6 years-14 years old with persistent asthma and an FEV1 ranging from 50% to 85% of predicted. A total of 87 patients in the montelukast group and 51 patients in the placebo group were selected from the original cohort of 336 patients based on percentage predicted FEV1 of > 75%. The primary endpoint was percentage change in FEV1 from baseline compared with placebo over 8 weeks of active treatment. RESULTS: Montelukast significantly improved the primary endpoint of percentage change in FEV1 compared with placebo (p = 0.005). Other efficacy endpoints were significantly improved on montelukast similar to efficacy in the original study. CONCLUSION: Montelukast significantly improved FEV1, clinic measured peak expiratory flow (PEF), reduced nocturnal awakenings, and improved quality of life in children with milder persistent asthma defined as an FEV1 > 75% of predicted.

Acetates↗
PubMed2002

Characterization of neurotransmitters and dopamine attenuation of inducible nitric oxide synthase in glioma cells.

Inducible nitric oxide synthase (iNOS) plays a significant role in the pathology of central nervous system diseases. Inducible NOS expression is regulated by intracellular adenosine 3',5'-cyclic monophosphate (cAMP) signaling, and astrocytes contain both iNOS and adenylate cyclase-coupled neurotransmitter receptors. The data obtained from the present study indicated that acetylcholine, lambda-amino-n-butyric acid, glutamate, quinolinic acid, N-methyl-D-aspartate and aspartate have no effect on NO(2)(-) production in C6 glioma cells stimulated by lipopolysaccharide and interferon-gamma. However, dopamine (DA) caused inhibition of NO(2)(-) production and iNOS transcription. The effects of DA were not due to homovanillic acid/3,4-dihydroxyphenylacetic acid, the autoxidative products superoxide (O(2)(-))/hydrogen peroxide (H(2)O(2)) or direct reactions with NO(2)(-). Forskolin, adenylate cyclase activator, dose-dependently reduced NO(2)(-). Meanwhile, (+/-) SKF-38393 D(1) receptor agonist attenuated iNOS in a similar fashion to DA. In addition, the results indicated that DA attenuation of iNOS was significantly impeded by the adenylate cyclase inhibitor MDL-12,330A, the D(1) antagonist SCH-23390, the beta2 adrenergic receptor antagonist ICI-118,551 and the beta1 adrenergic receptor antagonist atenolol. In conclusion, it appears that DA attenuates iNOS through a D(1), beta1 and beta2 adrenergic receptor-linked adenylate cyclase-mediated cAMP cascade.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed2002

Effectiveness of and compliance to intervention measures in reducing house dust and cat allergen levels.

BACKGROUND: Allergic sensitization is a major risk factor in asthma. OBJECTIVE: To evaluate the effectiveness of and compliance to intervention measures in reducing levels of house-dust mite and cat allergen in the context of a randomized, controlled study in the primary prevention of asthma. METHODS: A total of 545 high-risk families were recruited prenatally and randomly assigned into the intervention group (n = 278) and the control group (n = 267). Intervention measures were instituted before birth of the infants and maintained for 12 months afterward in the intervention group and the control group received the usual care from their family physician. Dust samples were collected at six sites in the homes before birth and at specific intervals up to 24 months after birth for analysis of allergens. At 24 months, there were 244 families in the intervention group and 228 in the control group available for followup examination. RESULTS: House-dust mite avoidance measures, consisting of encasement of mattresses, pillows, and duvets, and hot-water washing of bedding were effective in reducing mite allergen in parents' mattresses to one-third from baseline, significantly lower than the control group, even at 24 months. The use of an acaricide did not reduce mite allergen levels in carpets and upholstered furniture. Seventeen intervention families gave up their cats but six families acquired a new one over a period of 24 months, similar to control families. Cat allergen levels decreased in all sites in the homes of those who removed the cat, similar in both groups. CONCLUSIONS: House-dust mite avoidance measures were effective in reducing house-dust mite allergen in mattresses, but not on floors. Reduction in cat allergen levels were evident for those families who got rid of their cats, but the advice to remove pets was not adhered to by most families.

Allergens↗
PubMedDate not supplied

Evaluation of asthma control by physicians and patients: comparison with current guidelines.

BACKGROUND: Current asthma consensus guidelines recommend a series of criteria for determining whether asthma is controlled. It is not known whether physicians are using these criteria to assess treatment needs and how effective such assessments are compared with patient assessment of asthma control. OBJECTIVE: To compare the parameters used by physicians and patients with asthma to determine whether asthma control is acceptable, according to the current Canadian asthma consensus guidelines. DATA AND METHODS: A total of 183 Canadian physicians, mostly general practitioners, evaluated 856 patients with mildly to moderately uncontrolled asthma who were not using anti-inflammatory medications at the time of entry in the study. Physician characteristics and patient demographics were obtained. The physicians completed two questionnaires, one assessing the level of asthma control of the patient on an ordinal scale from 1 (very poor) to 5 (very good) and another indicating the parameters that were used to evaluate this level of control. Patients answered an asthma control questionnaire identical to the one completed by the physician and completed a six-question asthma control questionnaire, with each question scored on a 0- to 6-point scale. RESULTS: Although according to current asthma guidelines all patients surveyed had uncontrolled asthma, 66.2% of patients and 43.3% of physicians rated control of asthma symptoms as adequate to very good. The average scores for patient- and physician-rated asthma control were 3.0 0.2 and 2.6 0.2, respectively. The average patient score on the Juniper asthma questionnaire was 12.2 6.3. Physicians used a mean of seven parameters to assess the patient's level of asthma control, mostly beta2-agonist need, followed by cough, wheezing, shortness of breath, limitation of physical activities and night-time awakenings. Pediatricians used cough more frequently as an evaluation parameter, and respirologists measured pulmonary function more often than other physcians. Some parameters not usually included in guideline criteria for control, such as fatigue, need to clear throat, colored sputum, headache and dizziness, were sometimes used by physicians. Only 10% and 18% of physicians used measurements of forced expiratory volume in 1 s and peak expiratory flow, respectively, in asthma control assessments. CONCLUSIONS: The present study shows that the selection of asthma control criteria among physicians varies and is not always in keeping with current asthma guidelines. Both patients and physicians often consider asthma to be controlled, when according to current guidelines, it is not, and patients consider their asthma better controlled than do physicians. Objective measures of airflow obstruction are rarely used to assess asthma control. The present study stresses the need for improved dissemination - to both patients and physicians - of current recommendations on how asthma control should be determined.

Adolescent↗
PubMedDate not supplied

Adult Asthma Consensus Guidelines update 2003.

BACKGROUND: Several sets of Canadian guidelines for the diagnosis and management of asthma have been published over the past 15 years. Since the last revision of the 1999 Canadian Asthma Consensus Report, important new studies have highlighted the need to incorporate new information into the asthma guidelines. OBJECTIVES: To review the literature on adult asthma management published between January 2000 and June 2003; to evaluate the influence of the new evidence on the recommendations made in the 1999 Canadian Asthma Consensus Guidelines and its 2001 update; and to report new recommendations on adult asthma management. METHODS: Three specific topics for which new evidence affected the previous recommendations were selected for review: initial treatment of asthma, add-on therapies in the treatment of asthma and asthma education. The resultant reviews were discussed in June 2003 at a meeting under the auspices of the Canadian Thoracic Society, and recommendations for adult asthma management were reviewed. RESULTS: The present report emphasises the importance of the early introduction of inhaled corticosteroids in symptomatic patients with mild asthma; stresses the benefit of adding additional therapy, preferably long-acting beta2-agonists, to patients incompletely controlled on low doses of inhaled corticosteroids; and documents the essential role of asthma education. CONCLUSION: The present report generally supports many of the previous recommendations published in the 1999 Canadian Asthma Consensus Report and provides higher levels of evidence for a number of those recommendations.

Adrenal Cortex Hormones↗