Feather or synthetic? That is the question.
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Allergens↗
Biomedical subjects
A Woodcock
Publications and source records attributed to A Woodcock.
Randomised controlled trial of patient centred care of diabetes in general practice: impact on current wellbeing and future disease risk. The Diabetes Care From Diagnosis Research Team.
OBJECTIVE: To assess the effect of additional training of practice nurses and general practitioners in patient centred care on the lifestyle and psychological and physiological status of patients with newly diagnosed type 2 diabetes. DESIGN: Pragmatic parallel group design, with randomisation between practice teams to routine care (comparison group) or routine care plus additional training (intervention group); analysis at one year, allowing for practice effects and stratifiers; self reporting by patients on communication with practitioners, satisfaction with treatment, style of care, and lifestyle. SETTING: 41 practices (21 in intervention group, 20 in comparison group) in a health region in southern England. SUBJECTS: 250/360 patients (aged 30-70 years) diagnosed with type 2 diabetes and completing follow up at one year (142 in intervention group, 108 in comparison group). INTERVENTION: 1.5 days' group training for the doctors and nurses-introducing evidence for and skills of patient centred care and a patient held booklet encouraging questions. MAIN OUTCOME MEASURES: Quality of life, wellbeing, haemoglobin A1c and lipid concentrations, blood pressure, body mass index (kg/m2). RESULTS: Compared with patients in the C group, those in the intervention group reported better communication with the doctors (odds ratio 2.8; 95% confidence interval 1.8 to 4.3) and greater treatment satisfaction (1.6; 1.1 to 2.5) and wellbeing (difference in means (d) 2.8; 0.4 to 5.2). However, their body mass index was significantly higher (d=2.0; 0.3 to 3.8), as were triglyceride concentrations (d=0.4 mmol/l; 0.07 to 0.73 mmol/l), whereas knowledge scores were lower (d=-2.74; -0.23 to -5.25). Differences in lifestyle and glycaemic control were not significant. CONCLUSIONS: The findings suggest greater attention to the consultation process than to preventive care among trained practitioners; those committed to achieving the benefits of patient centred consulting should not lose the focus on disease management.
Adult↗
ABC of allergies. Avoiding exposure to indoor allergens.
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Allergens↗
Effects of inhaled corticosteroids on bone density and metabolism.
Oral corticosteroids have adverse effects on bone density and metabolism. With the increased use of inhaled corticosteroids together with the use of higher doses for the treatment of asthma, the long-term effects of inhaled corticosteroids on bone metabolism and density must be evaluated. This article discusses the markers of bone resorption and formation together with techniques used to measure cortical and trabecular bone density. The effects of inhaled corticosteroids on bone density and metabolism as determined by these techniques are described in detail. Overall, inhaled corticosteroids are extremely safe, even at high doses, with the long-term risk of bone loss being extremely small compared with oral corticosteroids. In particular, fluticasone propionate at the recommended doses appears to be free of effects on bone density and metabolism. Finally, the use of inhaled corticosteroids results in the control of asthma, allowing patients to exercise, which itself improves bone density and protects against osteoporosis.
Administration, Inhalation↗
Domestic allergens in public places III: house dust mite, cat, dog and cockroach allergens in British hospitals.
BACKGROUND: Exposure and sensitization to indoor allergens is a major cause of asthma. OBJECTIVES: This study investigated the levels of house dust mite, cat, dog and cockroach allergens in the dust and air in hospitals and the effects of regular vacuum cleaning on allergen levels in hospital chairs. METHODS: Der p 1, Fel d 1, Can f 1 and Bla g 2 were measured in the dust collected by vacuuming upholstered chairs and a 1 m2 area of carpet and mattress in 14 hospitals. Air samples were collected using an air sampler (flow rate 60 L/min) on 10 separate days for 4 h in the outpatient department in one of the hospitals during busy clinics when patients were waiting for their appointments. In addition, dust samples were collected on four occasions, at 4-weekly intervals, from 36 fabric covered chairs in the outpatient area of a busy chest clinic by vacuuming each chair for 2 min. During the intervening weeks, 18 of the chairs (active group) were each cleaned by vacuuming for 1 min, three times per week. Der p 1, Fel d 1, Can f 1 and Bla g 2 were assayed using monoclonal antibody-based ELISA. RESULTS: In total, 83 carpets, 69 mattresses and 42 upholstered chairs were sampled. The levels of dust mite allergen Der p 1 and cockroach allergen Bla g 2 found in the hospital setting were low. High levels of Fel d 1 (GM 22.9 microg/g, range 4.5-58) and Can f 1 (GM 21.6 microg/g, range 4-63) were found in upholstered chairs. Airborne Can f 1 was detected on every occasion (range 0.12-0.56 ng/m3), whilst detectable airborne Fel d 1 was found on 7 out of the 10 sampling days (range 0.09-0.22 ng/m3). Der p 1 and Bla g 2 were below the detection limit in all airborne samples. Following repeated vacuuming the mean cat and dog allergen levels decreased significantly (P<0.001) and were almost fivefold lower in the vacuumed chairs compared with the control group. CONCLUSIONS: Low levels of mite allergen are unlikely to be of any clinical significance to mite-sensitive asthmatic patients. However, upholstered chairs in hospitals constitute a significant reservoir of cat and dog allergen. Inhalation of airborne allergen in patients attending their hospital appointment may exacerbate asthma in those highly allergic to cats or dogs. These results question the wisdom of introducing soft furnishings and carpets into hospitals. Three-times weekly vacuuming significantly reduces allergen levels in upholstered chairs.
Air Pollution, Indoor↗
Indoor environmental factors and respiratory illness.
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Air Pollution, Indoor↗
The effect of dry heat on mite, cat, and dog allergens.
BACKGROUND: Various techniques have been tried in an attempt to reduce allergen levels in homes. This study investigated the effect of dry heat on mite, cat, and dog allergens. METHODS: Samples (50 mg) of Dermatophagoides pteronyssinus and D. farinae cultures, and of house dust rich in the major cat and dog allergens Fel d 1 and Can f 1 were heated for 5, 10, 15, 30, and 60 min at 60 degrees, 80 degrees, 100 degrees, 120 degrees, and 140 degrees C. Control samples remained at room temperature. Extracts were assayed with the appropriate two-site mono- or mono/polyclonal sandwich ELISA. RESULTS: For Der p 1, the breakdown was proportional to temperature and heating time; after 30 min at 120 degrees C, allergen levels were reduced to < 1% of control. Der p 2 was more heat stable, requiring 140 degrees C for 30-60 min to achieve > 99% reduction. D. farinae groups 1 and 2 allergens showed results similar to those obtained with D. pteronyssinus. In contrast, Can f 1 and Fel d 1 were considerably more thermostable, with 50% and 70%, respectively, of allergen remaining after 60 min at 140 degrees C. CONCLUSIONS: The effect of dry heat on allergens increased with increasing time and temperature, cat and dog allergens demonstrating greater heat resistance than mite allergens. Dry heating methods may represent an alternative technique for removal of mite allergens; however, the greater stability of Fel d 1 and Can f 1 suggests that this procedure may not be appropriate for pet allergens.
Allergens↗
Variability of house-dust-mite allergen levels within carpets.
Sensitization and exposure to house-dust-mite allergens is an important cause of asthma. Standardized, reliable, and reproducible methods for measuring exposure are essential for the assessment of the relationship between exposure, sensitization, and asthma. This study investigated the variability of the house-dust-mite allergen Der p 1 concentration in reservoir dust collected within whole carpets in living rooms and bedrooms. The carpets of nine bedrooms and 11 living rooms were sampled. Each room was divided into 1 m2 areas measured from wall to wall where the carpet was accessible. Reservoir dust samples were collected by vacuuming each 1 m2 area for 2 min. Der p 1 was assayed by a two-site monoclonal-antibody-based immunometric ELISA. Der p 1 was detectable in the carpets of all nine bedrooms and six of the 11 living rooms. Within these 15 rooms, there was a wide range of Der p 1 levels. The smallest range of allergen within a single room was 0.9 microgram Der p 1/g dust (0.2 and 1.1 micrograms/g; 5.5-fold difference), and the largest was 149.2 micrograms Der p 1/g dust (0.8 and 150 micrograms/g; 192-fold difference). The mean range of allergen levels in the living rooms was 11.5 micrograms Der p 1/g of dust, and the mean coefficient of variation of these rooms was 80.2%, illustrating the huge variation of mite allergen levels within each room. The variation within bedrooms was also large, with a mean coefficient of variation value of 88.7%. The coefficient of variation was significantly lower around soft furnishings or beds (57%) than in the rest of the room (89.3%), with the mean difference being 32% (95% CI 2-63%; P = 0.04). In conclusion, this study has shown that there is a great variation of Der p 1 levels between areas within a room. No consistent pattern of distribution of mite allergen within a room was found. Der p 1 levels in areas around soft furnishings and beds varied less than the levels in the rest of the room.
Allergens↗
Importance of indoor allergens in the induction of allergy and elicitation of allergic disease.
During the last few decades, many countries have experienced an increase in the prevalence and severity of asthma. Over the same period, the population in the developed world has retreated indoors, and homes have become better insulated and more energy efficient, resulting in a warm and humid environment with low ventilation rates, ideally suited to house-dust-mite population growth throughout the year. Increasing exposure and increasing sensitivity to indoor allergens represent a progressively higher risk factor for the development of asthma. The development of sensitivity to indoor allergens and the symptoms and severity of asthma in later childhood are directly related to the exposure to allergens in infancy. It was relatively straightforward to demonstrate a quantitative linear dose-response relationship between exposure to house-dust-mite allergens and subsequent sensitization. However, showing the same for exposure and asthma severity has been more difficult, as the relationship between exposure and asthma symptoms in already sensitized individuals is much more complex than in the case of exposure and sensitization. Nevertheless, sensitized individuals are likely to have more severe asthma if exposed to high allergen levels than if their level of exposure is low. Sensitization to house-dust mites is a major independent risk factor for asthma in all areas where climate is conducive to mite population growth. The relevance of allergens other that mite is not consistent between different areas, and depends on the climate, habits, and socio-economic features of the local community. It would appear that presence of mite allergens in homes "overshadows" other allergens (e.g., cat, dog, or cockroach) as a risk factor for sensitization and subsequent development of allergic disease. It is possible that this is the consequence of the difference in inherent potency between allergen sources, and the question of why mite allergens are so potent in inducing sensitization and atopic disease remains to be answered.
Air Pollution, Indoor↗
Distribution, aerodynamic characteristics, and removal of the major cat allergen Fel d 1 in British homes.
BACKGROUND: Sensitisation to cat allergen (Fel d 1) is an important risk factor for asthma in the UK. A study was undertaken to investigate the distribution of cat allergen in British homes, the aerodynamic characteristics and particle size distribution of airborne Fel d 1, and the method of removing it. METHODS: Dust was collected from 50 homes with a cat and from 50 homes without a cat, and airborne levels of Fel d 1 were measured in 50 homes with a cat and 75 homes without a cat. Particle size distribution was determined using an Andersen sampler (8 hours/day) in 10 homes with cats. This was repeated on five separate days in a house with four cats, and then one, two, four, seven, and 14 days after the cats were removed from the living room area. The effect of high efficiency particulate air (HEPA) cleaner on airborne levels of Fel d 1 was investigated in seven homes with cats. Samples were collected on two separate days from two rooms of each house concurrently, one of which contained the cat, one day with the HEPA cleaner on and the other day as a control. Three one hourly samples were collected over a nine hour period (baseline, 4-5 hours, 8-9 hours) using a high volume dust sampler (air flow rate 60 l/min) and the air sample was collected onto a microglass fibre filter (pore size 0.3 micron). RESULTS: Fel d 1 concentrations were much lower in houses without a cat than in those with a cat (260-fold difference (95% CI 167 to 590) in living room carpets: geometric mean (GM) 0.9 microgram/g (range 0.06-33.93) versus 237 micrograms/g (range 2.8-3000); 314-fold difference (95% CI 167 to 590) in upholstered furniture: 1.21 micrograms/g (range 0.06-61.9) versus 380 micrograms/g (range 7.1-6000); 228-fold difference (95% CI 109 to 478) in bedroom carpets: 0.24 microgram/g (range 0.06-2.24) versus 55 micrograms/g (range 0.06-2304); and 215-fold difference (95% CI 101 to 456) in mattresses: 0.2 microgram/g (range 0.06-2.3) versus 55 micrograms/g (range 0.06-3400). Airborne levels of Fel d 1 were detected in all houses with cats, and the levels varied greatly between the homes (range 0.7-38 ng/m3). Low concentrations of airborne Fel d 1 (range 0.24-1.78 ng/m3) were found in 22 of 75 homes without a cat. Although airborne Fel d 1 was mostly associated with large particles (> 9 microns, approximately 49% of the allergen recovered), small particles (< 4.7 microns) comprised approximately 23% of the total airborne allergen. Total airborne Fel d 1 was reduced by 61.7% two days after removal of the cat but this was due predominantly to the decrease in larger particles (> 4.8 microns) which fell to 13% of their baseline level. Fel d 1 levels associated with small particles (< 4.8 microns) remained largely unchanged on days 1, 2 and 4 and then slowly decreased to 33% of the baseline levels at day 14. With HEPA cleaner a significant reduction in airborne Fel d 1 was observed compared with the control sampling (GM 5.04-0.88 ng/m3 versus 3.79-1.56 ng/m3 at baseline and 8 hours, active versus control group; p = 0.008). CONCLUSIONS: Airborne Fel d 1 was detectable in undisturbed conditions in all homes with cats and in almost a third of homes without cats. In houses with cats a significant proportion (23%) of airborne Fel d 1 was associated with small particles (< 4.7 microns diameter). Removal of the cat from the living room and bedroom areas of the home and the use of HEPA air cleaner reduced airborne levels of cat allergen in homes with cats, but the reduction following cat removal was not evenly spread across the particle size range.
Air Pollution, Indoor↗
Allergen avoidance in the treatment of asthma and atopic disorders.
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Air Pollutants↗
Bronchodilator response to salbutamol after chronic dosing with salmeterol or placebo.
It has been hypothesized that regular inhaled beta2-agonist therapy causes desensitization of beta2-receptors. The aim of this study was to define whether beta2-receptor desensitization occurs after treatment with the long-acting beta2-agonist salmeterol, assessed by measuring the bronchodilator response to cumulative repeated doses of inhaled salbutamol before and after treatment. Forty nine stable adult patients with asthma were randomized to receive either salmeterol 50 microg b.d. or placebo b.d. from an Accuhaler for 4 weeks after an initial 2 week run-in period without beta2-agonists. All patients were receiving inhaled corticosteroids. Bronchodilator responsiveness to cumulative repeated doses of inhaled salbutamol were measured before and 12 and 36 h after the last dose of study treatment. The primary efficacy endpoint was the peak forced expiratory volume in one second (FEV1) response before and after treatment. There were no significant differences between the two treatment groups in the absolute peak FEV1 or maximal peak expiratory flow (PEF) results 12 or 36 h after the last dose of study treatment. Significantly higher clinic lung function and diary card parameters were noted in the salmeterol group when compared to the placebo-treated patients, demonstrating the beneficial effects of regular salmeterol. Regular salmeterol usage did not lead to reduced efficacy of usual or higher than usual doses of salbutamol.
Adolescent↗
Whole population or high-risk group? Childhood asthma.
Allergen avoidance seems to be a logical way to protect high-risk children from the development of allergic diseases. If we assume that allergic diseases are predictable, we firstly need to define which allergic disease and what age we are discussing. Then the predictive capacity of risk factors, their clinical value and their prevalence in the population has to be considered. In newborns, the positive predictive value of family history and an elevated cord blood immunoglobulin E for atopic disorders in the first 2 yrs of life was well under 50% in high-risk cohorts. In the multicentre allergy study (MAS)-90 in Germany, 40% of children 3-5 yrs of age whose parents both had asthma, also had asthma themselves. However, when extrapolated to the population as a whole, most children with asthma would have no parent with asthma. Risk factors suitable for secondary prevention, such as presence and persistence of food antibodies or early atopic dermatitis together with an atopic family history may predict up to 80% of aeroallergen sensitization by 5 yrs. However, the sensitivity of these factors is also low. We therefore need better predictors for asthma and a policy for intervention strategies according to age and risk.
Adult↗
Use of spacers with metered dose inhalers.
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Administration, Inhalation↗
Significance of raised natriuretic peptides after bicaval and standard cardiac transplantation.
BACKGROUND: High levels of plasma atrial natriuretic peptide (ANP) and ventricular natriuretic peptide (BNP) have been identified after standard orthotopic cardiac transplantation. It has been postulated that the high ANP levels are a result of persistent secretion from the large residual atrial mass after transplantation. This study was undertaken to investigate the significance of raised ANP and BNP levels after standard and bicaval orthotopic heart transplantation. METHODS: Plasma ANP and BNP levels were measured in 40 ambulatory, randomly selected cardiac transplant patients (group A, n = 20 had bicaval transplantation; group B, n = 20 had standard transplantation) and 10 healthy volunteers (group C). Cardiac transplant patients underwent endomyocardial biopsy and hemodynamic evaluation. RESULTS: Plasma levels of ANP and BNP were elevated in the transplant recipients in comparison with normal volunteers (p = 0.0001 and p < 0.0001, respectively). There was no significant difference in the ANP levels between group A and group B, whereas BNP levels were higher in group B compared with group A (p = 0.03). Linear regression analysis showed that a faster heart rate, high mean pulmonary artery pressure, high pulmonary capillary wedge pressure, and high transpulmonary gradient were associated with higher levels of BNP (p < 0.05). Lower mean systemic pressure was associated with higher levels of ANP (p < 0.05). CONCLUSIONS: High levels of ANP and BNP are synthesized and secreted by the transplanted denervated human heart regardless of the surgical technique. The level of BNP correlates with ventricular performance and afterload. The bicaval technique seems to be associated with better left ventricular and right ventricular diastolic performance.
Adult↗
An assessment of steroid hypersensitivity in asthma.
In dermatological practice, allergy to topical corticosteroids used to treat eczema is a recognized and common event. The typical presentation is of an eczema which fails to improve or deteriorates with treatment. Topical corticosteroids are also used to treat mucosal disease. This study assesses allergy to inhaled corticosteroids in asthmatics. In the patient group selected, there was no evidence of relevant corticosteroid allergy.
Administration, Inhalation↗
Exercise induced bronchospasm in Ghana: differences in prevalence between urban and rural schoolchildren.
BACKGROUND: As more developing countries adopt a westernised style of living, an increase in the prevalence of asthma can be expected to occur in these areas. A study was undertaken to establish the normal response to exercise in Ghanaian children and to use these normal values to determine the prevalence of exercise induced bronchospasm (EIB) in urban rich (UR), urban poor (UP), and rural (R) school children. Skin test reactivity to common inhalant allergens in UR, UP, and R children with and without EIB was also investigated. METHODS: Two hundred children aged 9-16 years without a previous history of respiratory symptoms were randomly selected and underwent free running exercise testing. A normal response to exercise was defined as the group mean change in peak expiratory flow rate (PEFR) +/- 2 standard deviations. This value was used to identify the prevalence of EIB in UR, UP, and R schoolchildren. A total of 1095 children from three different schools underwent exercise testing (220 UP, 599 UR, 276 R), after which 916 children underwent skin prick testing to six common inhalant allergens (D farinae, D pteronyssinus, cat, dog, Aspergillus flavus and Candida albicans). RESULTS: From the results of exercise testing in asymptomatic children the normal range was defined as a fall in PEFR of < 12.5% after exercise. Thirty four children were classified as having EIB on the basis of the above definition, giving an overall prevalence of 3.1%. The prevalence of EIB was significantly higher in UR children (4.7%) than in both UP (2.2%; p < 0.05) and R children (1.4%; p < 0.01). However, the prevalence rates in the UP and R children were similar. The prevalence of atopy in the whole population was 4.4%. Of the children with EIB, 10% were skin test positive to at least one of the allergens tested. The prevalence of atopy was significantly higher in UR children (6.55%, 95% confidence interval (CI) 4.5% to 9.2%) than in UP (2.9%, 95% CI 0.9% to 6.7%) and R children (1.5%, 95% CI 0.4% to 3.7%), respectively (p < 0.005). CONCLUSIONS: The prevalence of EIB and atopy is higher in urban rich than in urban poor or rural children suggesting that, in addition to genetic predisposition, social and environmental factors such as wealth, life style, and housing are important determinants of these phenotypes.
Adolescent↗
Aerodynamic properties of the major dog allergen Can f 1: distribution in homes, concentration, and particle size of allergen in the air.
Exposure and sensitization to dog allergen is a significant cause of asthma. In this study we investigated the distribution, aerodynamic characteristics, and particle-size distribution of the major dog allergen Can f 1. Dust samples were collected in 50 homes with a dog and 50 homes without dogs. Airborne Can f 1 concentration was measured in 28 homes with dogs and 36 homes without a dog. Particle-size distribution was determined by using 10 separate Andersen sampler measurements in a dog-handling facility, and in 10 homes with dogs, and by repeated measurements in a home with one dog. High levels of Can f 1 (> 10 microg/g) were found in dust in all but one home with a dog and in eight of 50 homes without dogs. Airborne Can f 1 levels varied greatly between the homes with dogs (range: 0.3 to 99 ng/m3). Low levels of airborne Can f 1 (range: 0.4 to 1.1 ng/m3) were detected in 11 of 36 homes without a dog. Can f 1 was predominantly associated with large particles collected on the first stage of the Andersen sampler (> 9 microm), which averaged 42 to 49% of the total allergen recovered in the dog-handling facility and in homes with dogs. Small particles (< 5 microm diameter) also carried Can f 1, and these particles comprised approximately 20% of the total airborne allergen load. There was an excellent concordance between the results obtained in different sampling areas, and between the total Can f 1 recovered on the Andersen sampler and on the parallel filter. In conclusion, airborne Can f 1 was detectable in undisturbed conditions in all homes with dogs and in almost one third of the homes without dogs. In houses with dogs, a significant proportion (approximately 20%) of airborne Can f 1 was associated with small particles (< 5 microm diameter). Owing to their aerodynamic characteristics, these particles would be expected to remain airborne for a long period and, when inhaled, could penetrate into the lower airways and initiate asthma attacks.
Air Pollution, Indoor↗