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At least 595 records · Page 33Linked to original sources
PubMed1998

Immunohistochemical characterization of the cellular infiltrate in airway mucosa of toluene diisocyanate (TDI)-induced asthma: comparison with allergic asthma.

Toluene diisocyanate (TDI) is the most prevalent agent in occupational asthma (OA) in Korea. The immuno-pathologic mechanism for TDI-induced bronchoconstriction remains to be clarified. We studied the immunohistochemical finding of inflammatory cells in bronchial mucosa in subjects with TDI-induced asthma. Fiberoptic bronchial biopsy specimens were obtained from nine subjects with TDI-induced asthma. Six allergic asthma sensitive to house dust mite were enrolled as controls. Bronchial biopsy specimens were examined by immunohistology with a panel of monoclonal antibodies to mast cell tryptase (AA1), secretary form of eosinophil cationic protein (EG2), pan T-lymphocyte (CD3) and neutrophil elastase (NE). There was a significant increase in the number of AA1+, EG2+ and NE+ cells in TDI-induced asthma compared to those of allergic asthma (p=0.02, p=0.04, p=0.03, respectively). No significant differences were observed in the number of CD3+ cells (p=0.27). These findings support the view that neutrophil recruitment together with eosinophil and mast cell, may contribute to the bronchoconstriction induced by TDI.

Adult↗
PubMed1999

Prevalence of asthma, rhinitis and eczema among children in 2 Canadian cities: the International Study of Asthma and Allergies in Childhood.

BACKGROUND: Wide variations in the prevalence of asthma, rhinitis and eczema have been reported between regions within Canada and between different countries. The International Study of Asthma and Allergies in Childhood (ISAAC) was developed to provide a standardized tool and methodology to ascertain the prevalence of asthma and allergies in different regions. Comparisons of prevalence rates across geographic regions and at different times may help to identify factors that contribute to the development of these conditions in individuals. METHODS: Two Canadian centres, Hamilton and Saskatoon, participated in the ISAAC. A standard questionnaire was distributed through schools and completed by 13- and 14-year-old children and by the parents of 6- and 7-year-old children. Prevalence rates and 95% confidence intervals were calculated for asthma, wheezing, rhinitis and eczema. RESULTS: The overall response rates were 75.1% among the children 6 and 7 years old and 68.6% among those 13 and 14 years old. Among the younger children, the lifetime prevalence of asthma was 17.2% in Hamilton and 11.2% in Saskatoon; the corresponding rates among the older children were 19.2% and 12.2% respectively. The prevalence of wheezing in the 12 months before the survey in the younger group was 20.1% in Hamilton and 14.1% in Saskatoon; in the older group it was 30.6% and 24.0% respectively. The prevalence of rhinitis in the 12 months before the survey was 28.6% in Hamilton and 22.6% in Saskatoon in the younger group and 45.8% and 33.8% respectively in the older group. The prevalence of eczema was slightly higher in Saskatoon in both age groups. INTERPRETATION: High prevalence rates of asthma, rhinitis and eczema exist among school children in Hamilton and Saskatoon, similar to rates in other Western countries. Further studies are required to determine the factors associated with the high rates in the 2 regions and possible reasons for the higher rates in Hamilton.

Adolescent↗
PubMed2000

[Asthma death among adults in Japan 1995-1997. Analysis of 295 cases reported questionnaires sent to hospitals with more than 100 beds. Asthma Death Investigation Committee].

To clarify recent trends in adult asthma mortality, the Asthma Death Investigation Committee of Japan studied the clinical characteristics of 295 patients who died of asthma between 1995 and 1997. Males were slightly more than females among the death cases. Approximately half of the patients ranged in age from 60 to 79 years. Tendency to increase of death among young male adults continued. One third of the patient deaths involved the asphyxic type, while status asthmaticus was the cause death in 21.9%. Half of the asthmatics died in hospitals or emergency rooms, and places where the fatal attacks occurred were mainly patients' houses. The main cause fatal asthma attacks was respiratory infection, followed by fatigue, stress, and discontinuation of medication. Most of the patients were classified moderate or severe type of asthma 1 month before death. Histories of life-threatening attacks and hospitalization due to severe attacks, irregular visits to the hospital, low compliance, and insufficiency of corticosteroid treatment were suggested as the main risk factors in adult asthma deaths.

Adolescent↗
PubMedDate not supplied

Brittle asthma: a separate clinical phenotype of asthma?

There is now good evidence that brittle asthma should be regarded as a separate clinical phenotype of asthma at the severe end of the spectrum. Two types of brittle asthma can be identified. Type I is characterized by wide swings in peak expiratory flow (PEF) despite maximal therapy and type II by very sudden attacks out of the blue. Type I brittle asthma is more common in females and although the exact aetio-pathogenic mechanisms are not yet known, several factors including allergen sensitization (with exposure) and psychosocial factors may be important. Peak expiratory flow monitoring is essential for recognising these patients. Treatment of type I brittle asthma is difficult and needs to be holistic, with particular attention being paid to psychosocial factors where required. Continuous subcutaneous infusion of terbutaline (or salbutamol)) and dietary exclusion of relevant foods to which the patient may be allergic may be helpful in selected patients. Type II brittle asthma is less difficult to manage and includes the use of self-administered subcutaneous adrenaline to abort the rapidly developing exacerbations.

Allergens↗
PubMed2001

Physician/patient differences in the perception of asthma: impact on everyday life and level of the asthma control in Croatia.

The aim of the study was to compare physician/patient differences in the perception of asthma. The data were obtained by questionnaires from 156 physicians and 148 asthmatics in four urban regions in Croatia. On a "bad day", 62% of physicians and 16% of patients perceived respiratory symptoms with statistically significant difference. The patients described asthma impact in terms of reduced daily activities and experienced emotional problems. Asthma was estimated as controlled in 28% of adults and 49% of children, nevertheless, 45% of adults and 22% of children reported respiratory symptoms. The patients seem to be satisfied with asthma control that does not correspond to suppression of symptoms, whereas physicians neglect patients' emotional problems and asthma impact on everyday life. The differences in the perception of asthma may reflect differences in beliefs about health. Physicians see health as an absence of symptoms, whereas patients regard being healthy as "being able".

Activities of Daily Living↗
PubMed1999

[Pharmacological study on asthma-relieving decoction (dingchuan tang) treating asthma].

Asthma-relieving decoction (Dingchuan tang) is a famous prescription of treating asthma, but its pharmacology has been not reported. This experiment showed that Asthma-relieving decoction (Dingchuan tang) can protect experimental asthma that blending of histamine and acetylcholine caused (P < 0.05 [symbol: see text] P < 0.01), can resist external trachea smooth muscle's contracting that histamine caused (P < 0.01), and can promote secretion of phenol red of rat's respiratory tract (P < 0.01). Results indicated that Asthma-relieving decoction (Dingchuan tang) has significant effect of relieving asthma and expelling phlegm.

Acetylcholine↗
PubMed2003

Are the components of the Asthma Management Plan important in managing childhood asthma? A survey of general practitioners.

AIM: To gauge the importance and relevance placed by general practitioners on components of the National Asthma Campaign's 'Six step' Asthma Management Plan for childhood asthma. METHOD: A cross sectional postal survey of a national randomised sample of 824 GPs. RESULTS: Each component was considered to be 'quite' or 'very' important by at least 70% of respondents. All 11 components were rated to be either 'quite' or 'very' important by 44%, and 91% of respondents considered eight or more of the components to be 'quite' or 'very' important. Two characteristics were consistently associated with the rating of importance: gender, (women GPs generally showing higher ratings), and reported frequency of use of the Asthma Management Plan (frequent users rate importance more frequently). CONCLUSION: There were high levels of endorsement of the Asthma Management Plan for children with asthma.

Adolescent↗
PubMed2005

[Epidemiology of asthma and allergies. The prevalence of allergies increases worldwide, and asthma has reached his highest-ever prevalence in Europe: why?].

Up to 10% of adults and 35% of children worldwide suffer from asthma. The incidence of asthma is also higher in children than in adults, possibly owing to a "cohort" effect. Recent population-based studies show that the increase in the prevalence of asthma noted worldwide in the past 30 years has started to subside in industrialised countries. This phenomenon has been accompanied by a parallel increase in the use of asthma medications. Possible explanations for this increase include the "hygiene hypothesis", which implicates diminished exposure to microbial pathogens but was recently challenged by new biological and immunological findings. Asthma might result from the interactions between individual and environmental factors (diet, air pollution, etc.), but further investigations are needed to understand the precise pathophysiological mechanisms of asthma.

Adolescent↗
PubMed1990

[Asthma and gastroesophageal reflux. Outcome of asthma after longterm medical treatment of the reflux].

Over one half of the cases of chronic severe childhood asthma, refractory to conventional therapy and without other over aetiology, are associated to gastroesophageal reflux (GER). The aetiopathogenic role of GER in asthma is uncertain, and is only confirmed when therapy of the former induces evident improvement of the latter. We have instituted medical antireflux therapy over two years in 17 patients (17.6%) became asymptomatic after less than three months of therapy, and a further four (23.5%) by the sixth month. Seven patients showed clinical improvement by the third month (41%) and even a greater one by the sixth month, only very slight symptoms persisting thereafter. In three cases (17.6%) there was no improvement after two years of outcome of asthma and the persistence or not of pathological between the outcome of asthma and the persistence or not of pathological 24-hour pHmetry. On the contrary. macroscopic oesophagitis disappeared in the cases of asthma with good outcome, but persisted in all the cases who remained symptomatic. In conclusion, we consider that medical management of GER associated to asthma should be maintained for at least six months (if the clinical course so permits) before considering a surgical indication.

Adrenal Cortex Hormones↗
PubMed1988

Further investigation into the recent increase in asthma death rates: a review of 41 asthma deaths in Oregon in 1982.

Vital statistics indicate increasing mortality from asthma since 1978 in the United States, England and Wales, Australia, and New Zealand. In Oregon and Washington, combined asthma mortality increased by 87% between 1977 and 1983. We reviewed the records of all patients (N = 41) (1) who died in hospitals or nursing homes in Oregon in 1982 and (2) whose death certificates listed asthma as the cause. Patients were 34 to 90 years old and half had been smokers. We found that most young patients who died clearly had asthma and died suddenly during severe attacks. Patients aged 55 and over frequently had bronchitis, emphysema, or chronic obstructive pulmonary disease rather than uncomplicated asthma, and were treated less aggressively than young patients. Their cause of death was often due to multisystem disease rather than reversible airflow obstruction. Reported statistics probably overestimate the true asthma mortality rate in the older population in Oregon.

Acute Disease↗
PubMed1987

Prospective investigations in asthma. What have we learned from longitudinal studies about lung growth and senescence in asthma?

The natural history of lung growth and senescence in individuals with variable air flow obstruction or clinical asthma has been given less attention than the natural history of chronic airflow obstruction. This article reviews the information available on lung growth during childhood in persons with asthma and on the rate of decline of lung function during adult life in individuals with asthma or bronchial hyperresponsiveness. Lung growth appears to be relatively normal in most children with asthma but is reduced throughout childhood and adolescence in those with severe and persistent symptoms. It is not known if this reflects a failure to reach full growth or reversible bronchoconstriction. During adult life, clinical asthma is associated with a slight increase in the rate of decline in FEV1. In the middle-aged and elderly smoker it is virtually impossible to separate chronic bronchitis and asthma. Bronchial hyperresponsiveness appears to be associated with an increase in the rate of decline of lung function but it is not clear if this is a result of airway disease due to smoking or a true risk factor. Further research needs are identified.

Adult↗
PubMedDate not supplied

Experiments on the role of virus infections in the pathogenesis of bronchial asthma. The role of innate or acquired insufficiency or ergotropic adaptation in the mechanism of genesis of bronchial asthma.

UNLABELLED: The wide mosaic of congruent clinical and experimental observations led to the postulation that the cause of the pharmacological abnormality of the asthmatic patient, i.e. the immensely increased reactivity of the bronchial smooth muscles, is to be sought in an insufficiency of the beta-adrenergic receptor system. It is to be assumed that the so-called asthma diatheses is based inter alia on a genetically determined defect of the adenyl cyclase system. The role of previous infections of the respiratory tract in asthmagenesis should lie--following this working theory--not in a sensitization in the sense of an allergic reaction of the immediate type, but in the formation of a defective beta-adrenergic substance or in a blockade of the beta-receptor. A genetically determined innate defect of the beta-adrenergic receptors, or a defect acquired through infections of the respiratory tract, is hence likely to be the cause of the pathologically potentiated reactivity of the bronchia. It is likely that the infective stimuli--quite apart from this preparatory role--are later capable of triggering asthmatic paroxysms when the vegetative homeostasis is impaired. We know from the experiments of many authors that a blockade of the beta-receptors produced by chemical blocker substances, or by pertussis vaccine or various bacterial substances, results in a significant increase in bronchial reactivity towards histamine, serotonin, acetylcholine and other stimuli. We have shown in our experiments that heat-inactivated adeno viruses and influenza viruses also increase the anaphylactic shock reactivity and the histamine reactivity of the organism. On the basis of this working hypothesis, the pathomechanism of the asthmatic process is as follows in individual asthma forms: 1) In the 'purely" allergic asthma form, the antigen-antibody reaction that occurs after sensitization (i.e. formation of skin-sensitizing allergic antibodies of the class IgE) results in re-formation and release of slow-reacting-substances. RESULT: spasm of the bronchial muscles, asthmatic paroxysm. The expulsion of catecholamines that follows the release of slow-reacting-substances makes a decisive contribution to the reestablishment of the impaired homeostatic balance. It is to be assumed that this form of asthma both symptomatically and causally--using specific desensitization--can be influenced more easily than other forms of asthma with a more complicated pathogenic background. 2) In the second allergically determined form of asthma, we are confronted by the genetically fixed or acquired insufficiency of the beta-receptors in addition to the immunological mechanism. As a result of the innate or acquired blockade of the beta-receptive substance, or the relative dominance of the alpha-receptors, the catecholamines (that physiologically serve to maintain homeostasis) contribute to a protraction, intensification and perpetuation of the bronchial obstruction. In this way the asthmatic circulus vitiosus is complete...

Adenoviridae↗
PubMed1995

Proactive, nurse-run asthma care in general practice reduces asthma morbidity: scientific fact or medical assumption?

Nurse-run asthma care in general practice in the United Kingdom has become extremely common, particularly since the introduction of the 1990 contract for general practitioners, but there have been few controlled trials of the clinical effectiveness of this approach to asthma care. A study attempted to compare the outcome of asthma care over three years in two similar practices when one practice provided proactive, nurse-run care and the second continued with a traditional (reactive) approach, and to examine the process of care when such changes were introduced. Despite the investment of considerable resources, statistically significant differences could not be shown between the two practices using a comprehensive variety of outcome measures. This could be interpreted as meaning that nurse-run asthma care may be ineffective, but the negative outcome is much more likely to reflect difficulties in the manner in which the intervention practice sought to develop its service and in the research process. There were extensive methodological problems leading to a potential type 2 error. A randomized controlled trial of nurse-run asthma care would now be difficult to conduct, and so it may be necessary to accept nurse-run asthma care without definitive proof of its clinical effectiveness.

Adolescent↗
PubMed1995

Lipoxygenase inhibitor-provoked acute asthma in a patient with asthma relieved by aspirin.

BACKGROUND: A very small number of patients with asthma show symptomatic improvement after administration of aspirin and other cyclooxygenase inhibitors. The clinical features of such patients with so-called aspirin-relieved asthma are similar to those with aspirin-induced asthma, but the pathogenesis is unclear. METHODS: We encountered one confirmed aspirin-relieved asthma patient and investigated the effects of cyclooxygenase and lipoxygenase inhibitors on his condition. RESULTS: Our patient showed a marked improvement of the forced expiratory volume in one second (FEV1) after administration of aspirin and three other cyclooxygenase inhibitors (indomethacin, mefenamic acid, and ketoprofen). A 5-lipoxygenase inhibitor (AA861, Takeda, Japan), however, evoked acute asthma, and repeated administration of this drug resulted in some desensitization, but not complete tolerance. CONCLUSIONS: These results suggest an altered balance of arachidonic acid metabolism may play a critical role in the pathophysiology of aspirin-relieved asthma.

Acute Disease↗
PubMed1994

Integrated care for asthma: a clinical, social, and economic evaluation. Grampian Asthma Study of Integrated Care (GRASSIC)

OBJECTIVES: To evaluate integrated care for asthma in clinical, social, and economic terms. DESIGN: Pragmatic randomised trial. SETTING: Hospital outpatient clinics and general practices throughout the north east of Scotland. PATIENTS: 712 adults attending hospital outpatient clinics with a diagnosis of asthma confirmed by a chest physician and pulmonary function reversibility of at least 20%. MAIN OUTCOME MEASURES: Use of bronchodilators and inhaled and oral steroids; number of general practice consultations and hospital admissions for asthma; sleep disturbance and other restrictions on normal activity; psychological aspects of health including perceived asthma control; patient satisfaction; and financial costs. RESULTS: After one year there were no significant overall differences between those patients receiving integrated asthma care and those receiving conventional outpatient care for any clinical or psychosocial outcome. For pulmonary function, forced expiratory volume was 76% of predicted for integrated care patients and 75% for conventional outpatients (95% confidence interval for difference -3.6% to 5.0%). Patients who had experienced integrated care were more likely to select it as their preferred course of future management (75% (251/333) v 62% (207/333) (6% to 20%)); they saved 39.52 pounds a year. This was largely because patients in conventional outpatient care consulted their general practitioner as many times as those in integrated care, who were not also visiting hospital. CONCLUSION: Integrated care for moderately severe asthma patients is clinically as effective as conventional outpatient care, cost effective, and an attractive management option for patients, general practitioners, and hospital consultants.

Adult↗
PubMed1994

Effectiveness of routine self monitoring of peak flow in patients with asthma. Grampian Asthma Study of Integrated Care (GRASSIC).

OBJECTIVE: To evaluate the effectiveness of routine self monitoring of peak flow for asthma outpatients. DESIGN: Pragmatic randomised trial. SETTING: Hospital outpatient clinics and general practices in north east Scotland. MAIN OUTCOME MEASURES: Use of bronchodilators and inhaled and oral steroids; number of general practice consultations and hospital admissions for asthma; sleep disturbance and other restrictions on normal activity; psychological aspects of health including perceived control of asthma. RESULTS: After one year there were no significant differences between patients randomised between self monitoring of peak flow and conventional monitoring. However, those given a peak flow meter recorded an increase in general practice consultations that was nearly significant. Among patients whose asthma was judged on entry to be more severe, those allocated to self monitoring used more than twice as many oral steroids (2.2; 95% confidence interval 1.1 to 4.6). Patients who already possessed a peak flow meter at the start of the study recorded higher morbidity over the course of the year than those eligible for randomisation. CONCLUSION: Prescribing peak flow meters and giving self management guidelines to all asthma patients is unlikely to improve mortality or morbidity. Patients whose asthma is severe may benefit from such an intervention.

Ambulatory Care↗
PubMed1996

A community trial of a written self management plan for children with asthma. Asthma Foundation of NZ Children's Action.

AIMS: To determine the effect of introducing an action plan to children with mild to moderate asthma, who have never used a plan before. METHODS: Children were recruited from general practitioner records with a diagnosis of asthma, and who agreed to participate, having identified that they had not used an action plan before and that they had mild or moderate asthma based upon symptoms, acute episodes and the need for preventative medication. The families were given a plan, and its use was explained to them by their general practitioner. A symptom diary was kept, and, where appropriate, peak flow measurements were recorded. A number of outcomes were measured to determine changes that could be attributed to the introduction of the plan. RESULTS: Following the introduction of the plan, the percentage of nights woken for asthma fell from 18.2% to 12.2% (P<0.001) and the number of days out of action fell from 6.4 to 4.1 (P<0.001). The requirement for acute medical treatment also fell during the intervention period with general practitioner visits falling from 129 to 42 (p<0.001). Most participants commented favourably about the usefulness of the plan in giving them a better idea of the state of their asthma at any time, and in knowing what to do about it. CONCLUSIONS: The children's action plan, when introduced into a group of asthmatic children was effective and acceptable in the self management of asthma.

Asthma↗
PubMed1996

Guidelines for the emergency management of asthma in adults. CAEP/CTS Asthma Advisory Committee. Canadian Association of Emergency Physicians and the Canadian Thoracic Society.

OBJECTIVE: To develop a set of comprehensive, standardized evidence-based guidelines for the assessment and treatment of acute asthma in adults in the emergency setting. OPTIONS: The use of medications was evaluated by class, dose, route, onset of action and optimal mode of delivery. The use of objective measurements and clinical features to assess response to therapy were evaluated in relation to the decision to admit or discharge the patient or arrange for follow-up care. OUTCOMES: Control of symptoms and disease reflected in hospital admission rates, frequency of treatment failures following discharge, resolution of symptoms and improvement of spirometric test results. EVIDENCE: Previous guidelines, articles retrieved through a search of MEDLINE, emergency medical abstracts and information from members of the expert panel were reviewed by members of the Canadian Association of Emergency Physicians (CAEP) and the Canadian Thoracic Society. Where evidence was not available, consensus was reached by the expert panel. The resulting guidelines were reviewed by members of the parent organizations. VALUES: The evidence-based methods and values of the Canadian Task Force on the Periodic Health Examination were used. BENEFITS, HARMS AND COSTS: As many as 80% of the approximate 400 deaths from asthma each year in Canada are felt to be preventable. The use of guidelines, aggressive emergency management and consistent use of available options at discharge are expected to decrease the rates of unnecessary hospital admissions and return visits to emergency departments because of treatment failures. Substantial decreases in costs are expected from the use of less expensive drugs, or drug delivery systems, fewer hospital admissions and earlier return to full activity after discharge. RECOMMENDATIONS: Beta2-agonists are the first-line therapy for the management of acute asthma in the emergency department (grade A recommendation). Bronchodilators should be administered by the inhaled route and titrated using objective and clinical measures of airflow limitation (grade A). Metered-dose inhalers are preferred to wet nebulizers, and a chamber (spacer device) is recommended for severe asthma (grade A). Anticholinergic therapy should be added to beta 2 agonist therapy in severe and life-threatening cases and may be considered in cases of mild to moderate asthma (grade A). Aminophylline is not recommended for use in the first 4 hours of therapy (grade A). Ketamine and succinylcholine are recommended for rapid sequence intubation in life-threatening cases (grade B). Adrenaline (administered subcutaneously or intravenously), salbutamol (administered intravenously) and anesthetics (inhaled) are recommended as alternatives to conventional therapy in unresponsive life-threatening cases (grade B). Severity of airflow limitation should be determined according to the forced expiratory volume at 1 second or the peak expiratory flow rate, or both, before and after treatment and at discharge (grade A). Consideration for discharge should be based on both spirometric test results and assessment of clinical risk factors for relapse (grade A). All patients should be considered candidates for systemic corticosteroid therapy at discharge (grade A). Those requiring corticosteroid therapy should be given 30 to 60 mg of prednisone orally (or equivalent) per day for 7 to 14 days; no tapering is required (grade A). Inhaled corticosteroids are an integral component of therapy and should be prescribed for all patients receiving oral corticosteroid therapy at discharge (grade A). Patients should be given a discharge treatment plan and clear instructions for follow-up care (grade C). VALIDATION: The guidelines share the same principles of those from the British Thoracic Society and the National Institutes of Health. Two specific validation initiatives have been undertaken: (a) several Canadian centres have been involved in the collection of comprehensive administrative data to assess compliance and outcome measures and (b) a survey of Canadian emergency physicians conducted to gather baseline informaton of treatment patterns, was conducted before development of the guidelines and will be repeated to re-evaluate emergency management of asthma.

Adult↗