Biomedical subjects

A Woodcock

Publications and source records attributed to A Woodcock.

At least 19 recordsLinked to original sources

PubMed2006

Objective measurement of cough during pulmonary exacerbations in adults with cystic fibrosis.

BACKGROUND: Little is known about cough frequency in adults with cystic fibrosis (CF). This study aimed to determine (1) daytime and overnight cough rates in patients with CF at the beginning and end of a course of antibiotics for treatment of an exacerbation; (2) the relationship between cough frequencies and standard clinical measures of disease; and (3) the relationship between objective cough rates and the subjective assessment of cough. METHODS: Nineteen adult patients admitted with a pulmonary exacerbation performed daytime and overnight sound recordings on admission; 13 had repeat recordings prior to discharge. Coughs were manually quantified in cough seconds (time spent coughing). Patients subjectively scored their cough using a visual analogue scale (VAS) and numerical score. Lung function, C-reactive protein (CRP) levels, and sputum weights were recorded. RESULTS: Cough rates fell substantially with treatment; median fall in cough rate was 51.3% (IQR 32.3-77.5) (p<0.001) for daytime and 72.2% (28.6-90.1) (p = 0.049) for overnight. Multivariate regression analyses showed that forced expiratory volume in 1 second and CRP levels predicted overnight cough rates on admission. On discharge, sputum volume predicted daytime cough rates. Only the change in overnight VAS correlated with the change in objective cough rates. CONCLUSIONS: The cough rate significantly decreases with treatment of a pulmonary exacerbation in adults with CF. Lung function, sputum volume, and CRP influences the cough rate, with the effects differing from day to night and between admission and discharge. Subjective reporting of a nocturnal cough may indicate a pulmonary exacerbation of CF in adults.

Adult↗

PubMed2006

Dietary intake in sensitized children with recurrent wheeze and healthy controls: a nested case-control study.

BACKGROUND: The rising prevalence of asthma and allergic disease remains unexplained. Several risk factors have been implicated including diet, in particular poly-unsaturated fats and antioxidant intake. METHODS: A nested case-control study comparing the dietary intake of sensitized children with recurrent wheeze (age 3-5 years) and nonsensitized children who had never wheezed was carried out within an unselected population-based cohort. Cases and controls were matched for age, sex, parental atopy, indoor allergen exposure and pet ownership. Dietary intake was assessed using a validated semi-quantitative food frequency questionnaire and nutrient analysis program. RESULTS: Thirty-seven case-control pairs (23 male, mean age 4.4 years) participated. Daily total polyunsaturated fat intake was significantly higher in sensitized wheezers (g/day, geometric mean, 95% confidence intervals: 7.1, 6.4-7.9) compared with nonsensitized nonwheezy children (5.6, 5.0-6.3, P = 0.003). Daily omega-3 and omega-6 fat intakes were not significantly different between the two groups. No significant differences were found in intake of any antioxidant or antioxidant cofactors between the groups. CONCLUSIONS: Young sensitized wheezy children had a significantly higher total polyunsaturated fat intake compared with nonsensitized nonwheezy children. However, we were unable to distinguish a significant difference in specific poly-unsaturated fat intakes. Otherwise the children in both groups had a very similar nutritional intake.

Antioxidants↗

PubMed2006

High-efficiency vacuum cleaners increase personal mite allergen exposure, but only slightly.

BACKGROUND: High-efficiency particulate-arrest-filter vacuum cleaners are recommended to allergy sufferers although their use increases personal cat allergen exposure. We aimed to measure personal mite allergen exposure during vacuum cleaning by nasal air sampling and to compare exposures while vacuuming and emptying the vacuum cleaner bag. METHODS: Five brand new high-efficiency vacuum cleaners were selected. An old, previously used vacuum cleaner with its original microfilter in situ was used as a control. Nasal air samples were taken prior to and during vacuum cleaning in 10 homes. Samples were processed by HALOgen assay. Personal mite and cat allergen exposure was measured as the dust compartments were emptied. RESULTS: There was an increase in personal mite allergen exposure with vacuum cleaning, which approached significance (P = 0.058). There was no difference between the high-efficiency vacuum cleaners and the control vacuum cleaner (P = 0.141). When the dust compartments were emptied, personal mite and cat allergen exposure increased (P < 0.02). CONCLUSIONS. The increase in personal mite allergen exposure while vacuum cleaning in an area with mild to moderate mite allergen exposure is small. High-efficiency vacuum cleaners confer no benefit and cannot currently be recommended to allergy sufferers as a means of reducing personal mite allergen exposure.

Air Pollution, Indoor↗

PubMed2006

Effect of age related macular degeneration on the Eger macular stressometer photostress recovery time.

AIM: To assess the repeatability of Eger macular stressometer (EMS) measures of photostress recovery and determine their association with other measures of visual function. METHODS: EMS photostress recovery time was measured in 90 patients with bilateral exudative age related macular degeneration (AMD), 19 with bilateral atrophic AMD and 47 with both forms of the condition (mean age 79 (SD 13) years). Measurements were made on two occasions separated by 1 year. Intrasession repeatability was assessed by repeating the measures after a 10 minute recovery period at the first visit. Distance visual acuity was measured with a logMAR chart, near visual acuity with a MNRead chart at 25 cm, contrast sensitivity with a Pelli-Robson chart, and the presence of central visual disturbance assessed with an Amsler grid. A questionnaire was used to assess self reported difficulties with glare recovery. RESULTS: The average EMS recovery time was 11.0 (SD 8.9) seconds, decreasing by 1.6 (5.2) seconds on repeated measurement (p<0.05). EMS photostress recovery was not correlated with visual function measures or subjective difficulties with lights (p>0.05). EMS photostress recovery time did not predict those whose vision decreased over the following year compared with those among whom it remained stable. CONCLUSIONS: The EMS test is not a useful tool in determining the severity or progression of AMD.

Adaptation, Ocular↗

PubMed2005

Study of modifiable risk factors for asthma exacerbations: virus infection and allergen exposure increase the risk of asthma hospital admissions in children.

BACKGROUND: Asthma exacerbation is the most common cause of hospital admission in children. A study was undertaken to investigate the importance of allergen exposure in sensitised individuals in combination with viral infections and other potentially modifiable risk factors precipitating asthma hospital admission in children. METHODS: Eighty four children aged 3-17 years admitted to hospital over a 1 year period with an acute asthma exacerbation (AA) were matched for age and sex with two control groups: stable asthmatics (SA) and children admitted to hospital with non-respiratory conditions (IC). Risk factors were assessed by questionnaires and determination of allergen sensitisation, home allergen exposure, pollen exposure, and respiratory virus infection. RESULTS: Several non-modifiable factors (atopy, duration of asthma) were associated with increased risk. Among the modifiable factors, pet ownership, housing characteristics, and parental smoking did not differ between the groups. Regular inhaled corticosteroid treatment was significantly less common in the AA group than in the SA group (OR 0.2, 95% CI 0.1 to 0.6; p = 0.002). A significantly higher proportion of the AA group were virus infected (44%) and sensitised and highly exposed to sensitising allergen (76%) compared with the SA (18% and 48%) and IC groups (17% and 28%; both p<0.001). In a multiple conditional logistic regression (AA v SA), allergen sensitisation and exposure or virus detection alone were no longer independently associated with hospital admission. However, the combination of virus detection and sensitisation with high allergen exposure substantially increased the risk of admission to hospital (OR 19.4, 95% CI 3.7 to 101.5, p<0.001). CONCLUSIONS: Natural virus infection and real life allergen exposure in allergic asthmatic children increase the risk of hospital admission. Strategies for preventing exacerbations will need to address these factors.

Adolescent↗

PubMed2005

Abacavir compared to protease inhibitors as part of HAART regimens for treatment of HIV infection: patient satisfaction and implications for adherence.

The purpose of this study was to compare treatment satisfaction with triple nucleoside reverse transcriptase inhibitor (NRTI) highly active antiretroviral treatment (HAART) regimens including abacavir (ABC) to HAART regimens that include protease inhibitors (PIs) and to estimate the relationship between patient satisfaction and adherence to HAART. Three open-label clinical trials comparing ABC-including HAART regimens with PI-including HAART regimens were completed, two with patients previously untreated with antiretroviral therapy and one with patients successfully treated with PI-including HAART regimens. The HIV Treatment Satisfaction Questionnaire (HIVTSQ) was completed at several time points during each trial. Levels of patient satisfaction with the ABC and PI regimens were compared for all three trials. The correlation between adherence and patient satisfaction scores was measured using data from an adherence questionnaire in one of the studies. In all three clinical trials, patient satisfaction scores were significantly higher with an ABC-including triple NRTI HAART regimen than with a PI-including HAART regimen. The difference was apparent by week 4 of the trial and was maintained throughout the trial time period. Inspection of the item responses in the patient satisfaction questionnaire indicated that treatment convenience, flexibility, impact on lifestyle, and side effects were key factors in the difference in satisfaction between the treatment groups. In addition, patient satisfaction was shown to be significantly correlated with adherence defined as taking 95% or more of prescribed doses. Greater satisfaction was reported by patients given an ABC-including HAART regimen than those given a PI-including HAART regimen. Patient satisfaction may be an indicator for better treatment adherence.

Adult↗

PubMed2005

Fecal microbiota in sensitized wheezy and non-sensitized non-wheezy children: a nested case-control study.

BACKGROUND: It has been suggested that intestinal microbiota of allergic and non-allergic children differs in composition, and that microbiota-immune system interactions may predispose children to develop sensitization. Previous studies have examined fecal microbiota of allergic children with atopic dermatitis, but little is known about that of atopic wheezy children. OBJECTIVE: To investigate the composition of the fecal microbiota of young sensitized wheezy and non-sensitized non-wheezy children, using molecular methods. METHODS: Within the context of a prospective birth cohort, we carried out a nested case-control study of sensitized wheezy children (cases) and non-sensitized non-wheezy controls. Cases and controls were matched for age, sex, parental atopy, allergen exposure, and pet ownership. We evaluated the composition of fecal microbiota by nucleic acid-based methods (PCR combined with denaturing gradient gel electrophoresis and quantification of bifidobacteria by fluorescent in situ hybridization). RESULTS: Thirty-three case-control pairs (mean age 4.4 years) provided stool samples. Comparison of total bacterial community profiles showed that each child had a unique fecal microbiota (mean Dice's similarity coefficient 22%, range 3.3-60.8%). There was no difference between the groups in prevalence of Lactic Acid bacteria (12/33 vs. 11/33, P=0.8) or bifidobacteria (30/33 vs. 31/33, P=1.00, cases vs. controls). The bifidobacterial species detected were similar in both groups. The percentage of bifidobacteria in total fecal microflora was no different between cases (median 1.7%, range 0-20.8%) and controls (1.9%, 0-18.2%, P=0.7). However, cases with eczema had significantly fewer bifidobacteria (median 1.6%, range 0-4.8%) than their controls (4.0%, 1.9-18.2%, P=0.05). CONCLUSION: We found no differences in fecal microbiota composition between sensitized wheezy and non-sensitized, non-wheezy children aged 3-5 years using nucleic acid-based methods. Differences appear to be isolated to those allergic children with eczema.

Bifidobacterium↗

PubMed2005

Effect of Mycobacterium vaccae on cytokine responses in children with atopic dermatitis.

The increasing prevalence of atopic diseases over the last few decades is thought to be due to reduced exposure to environmental microbes that normally down-regulate allergic responses (hygiene hypothesis). We have shown previously that administration of the environmental microbe Mycobacterium vaccae ameliorates atopic dermatitis in school-age children at 3 months post-treatment. The present study tested the hypothesis that M. vaccae suppresses Th2-type cytokine activity and increases transforming growth factor (TGF)-beta(1) immunomodulatory activity in these children. Interleukin (IL)-4, IL-5, TGF-beta(1) and interferon (IFN)-gamma activity were assessed in resting and stimulated peripheral blood mononuclear cells (PBMC) isolated from 12 of the children who received M. vaccae in our original clinical trial. A cDNA expression array was used to examine a broader range of cytokine pathway transcripts. There were no significant changes in either Th2-type or TGF-beta(1) activity. A 5- to 10-fold increase in Th1-type activity was found at 1 month post-M. vaccae administration (P < 0.05), but it had returned to baseline by 3 months. The results do not support the hypothesis that M. vaccae reduces Th2-type or increases TGF-beta(1) activity of PBMC isolated from children with atopic dermatitis. The transient surge in IFN-gamma at 1 month is unlikely to explain any improvement in eczema score at 3 months.

Adolescent↗

PubMed2005

The information needs and preferred roles in treatment decision-making of parents caring for infants with atopic dermatitis: a qualitative study.

BACKGROUND: Information needs and preferences in treatment decision-making of parents caring for infants with atopic dermatitis (AD) are unknown, despite emphasis on quality information-giving and involvement of health-care users in treatment decisions. OBJECTIVE: To explore information needs and decisional role-preferences of parents caring for infants with AD. METHODS: Qualitative study. Purposive sample: 31 parents caring for infants with AD. Tape-recorded focussed conversation-style interviews. Interview topic-guide literature-derived. Control Preferences Scale (5 sort-card vignettes 'very active' to 'very passive' role) adapted for use with parents; used to facilitate discussion. Thematic analysis of verbatim transcripts. RESULTS: Nine core information needs identified: AD-causation, role of diet, medication-use, medication-side-effects, exacerbating factors, new/alternative medication, nonpharmacological treatments, AD-prevention, AD and other atopic conditions. Parents desired verbal and written information. Many felt their baby's condition was not taken seriously, leading to delayed diagnosis and treatment. They had to be more active than they wished to obtain information/treatment. Parents preferred sharing decisions with their doctor. CONCLUSIONS: Parents caring for infants with AD have clearly defined, unmet information needs, forcing them into more active roles in the treatment decision-making process than they desire. The study-findings may inform the development of written information specifically for these parents and improve partnership during consultations.

Adult↗

PubMed2005

Development and psychometric validation of the veterinary service satisfaction questionnaire (VSSQ).

In the absence of a widely available, psychometrically tested questionnaire for measuring satisfaction with UK veterinary services, the Veterinary Service Satisfaction Questionnaire (VSSQ) was developed. Items in the first draft were derived from a literature review, guidelines from professional bodies and interviews with pet owners and veterinarians. The questionnaire includes 72 satisfaction items, each with a five-option response format. A total of 183 domestic pet owners from three small animal practices (60% response rate) completed it by mail. Pilot testing and postal completion rates indicate the acceptability and relevance of the VSSQ. Principal components analyses of respondent ratings suggested that the VSSQ can be scored as five scales: general services, staff communication, vet communication, death of pet and vet technical abilities. Six further items are scored separately. Descriptive statistics are provided for individual items and scales. Subgroup differences are explored according to owners' demographic variables. The VSSQ demonstrates preliminary face and content validity, excellent internal consistency reliability in each of the five scales (Cronbach's alpha 0.93-0.97) and good construct validity: those who had recommended the practice to others had significantly higher scores. Scoring guidelines are provided for the VSSQ, which is now ready for use.

Adult↗

PubMed2005

Relationship between exposure to domestic allergens and bronchial hyperresponsiveness in non-sensitised, atopic asthmatic subjects.

BACKGROUND: The effect of exposure to allergens not causing sensitisation in atopic asthmatic subjects has not previously been studied. A study was undertaken to assess the degree of asthma severity (measured by spirometry, airway reactivity and exhaled nitric oxide) in atopic asthmatic patients not sensitised to the domestic allergen to which they were exposed. METHODS: Dust samples were collected from the living room carpet and mattress in the homes of 248 subjects and dust mite, cat and dog allergen concentrations were measured. Spirometry, non-specific bronchial reactivity (BR), and exhaled nitric oxide (eNO) were ascertained. Patients' sensitisation status was assessed by skin prick testing. RESULTS: Adult atopic asthmatics not sensitised to mite but exposed to high levels of mite allergen had significantly more severe BR than subjects not exposed to high levels of mite (PD(20), geometric mean (GM) 0.21 mg (95% CI 0.09 to 0.47) v 0.86 mg (95% CI 0.44 to 1.67), mean ratio difference 4.1 (95% CI 1.5 to 11.4), p=0.008). Subjects not sensitised but exposed to high levels of dog allergen also had significantly more severe BR than subjects not exposed (PD20 GM 0.16 v 0.52 mg, mean ratio difference 3.3 (95% CI 1.2 to 9.2), p=0.01). The differences in BR between these groups were still significant after adjusting for confounding factors. This effect of greater airway reactivity was not seen in subjects exposed but not sensitised to cat allergens. CONCLUSION: Atopic asthmatic subjects who are exposed to high levels of dust mite or dog allergens but not sensitised to these allergens have evidence of increased airway reactivity.

Adolescent↗

PubMed2005

Involvement in treatment decisions: what do adults with asthma want and what do they get? Results of a cross sectional survey.

BACKGROUND: Current healthcare policy advocates patient participation in treatment decision making. However, in asthma there is little evidence regarding patients' views on such involvement. This study explored the preferred and perceived level of involvement in treatment decisions, rationales for role preference, perceived facilitators of/barriers to involvement, and the interrelationship of role preference and demographic variables in a sample of patients with asthma. METHODS: A cross sectional survey was performed of 230 adults with clinician diagnosed asthma from 10 primary care sites and one specialist respiratory centre in north-west England. Preferred role in treatment decisions was assessed using the Control Preferences Scale. RESULTS: Fifty five (23.9%) preferred an active role, 82 (35.7%) a collaborative role, and 93 (40.4%) a passive role; 19 (8.2%) perceived their role as active compared with 45 (19.6%) collaborative and 166 (72.2%) passive. Only 33.5% (n = 77) of respondents attained their most preferred role; 55.2% (n = 127) were less involved than they preferred. Patient related, professional related, and organisational factors, especially quality and duration of consultations, facilitated or hampered involvement. Role preferences were not strongly associated with demographic variables or asthma severity. CONCLUSIONS: This study in patients with asthma highlights the fact that there is a need for professional and patient education regarding partnership working, skilful communication, and innovative approaches to service delivery.

Adult↗

PubMed2004

Design of new questionnaires to measure quality of life and treatment satisfaction in hypothyroidism.

INTRODUCTION: This paper reports work undertaken to design two new condition-specific questionnaires for use in hypothyroidism: the Underactive Thyroid-Dependent Quality of Life Questionnaire (ThyDQoL) and the Underactive Thyroid Treatment Satisfaction Questionnaire (ThyTSQ). METHODS: Semistructured interviews exploring quality of life (QoL) and experiences of treatment were conducted with 30 women and 8 men with hypothyroidism, (mean age, 51.9; range, 29-79 years), 37 of 38 treated with thyroxine, recruited from hospital clinics and primary care. RESULTS: Despite thyroxine treatment, most interviewees reported negative impact of hypothyroidism on QoL, particularly on energy, physical capabilities, motivation, physical appearance, and weight. The newly designed ThyDQoL has 18 domains covering these and other aspects of life affected by hypothyroidism. It is an individualized measure of patients' perceived impact of hypothyroidism on their QOL, which takes into account the importance of personally applicable life domains to the patient. A 7-item measure of satisfaction with current treatment was designed (ThyTSQ-Present) but interviews also indicated the need for a separate 4-item section measuring satisfaction with past treatment around the time of diagnosis (ThyTSQPast). CONCLUSIONS: The ThyDQoL and ThyTSQ questionnaires have good face validity and content validity for adults with hypothyroidism. They are now ready for use in clinical research and psychometric evaluation.

Adult↗

PubMed2004

Comparison of bronchoprotective and bronchodilator effects of a single dose of formoterol delivered by hydrofluoroalkane and chlorofluorocarbon aerosols and dry powder in a double blind, placebo-controlled, crossover study.

BACKGROUND: In response to the phasing out of chlorofluorocarbon (CFC) inhalers, a metered dose hydrofluoroalkane (HFA) formulation, Modulite (Chiesi Farmaceutici S.p.A, Parma, Italy), to be delivered with a pressurized metered dose inhaler (pMDI), has been developed. Modulite is a HFA formulation technology that has been designed to provide stable and uniform dose delivery of HFA-based formulations to enable an easy transition from CFC to HFA inhalers. OBJECTIVES: The aim of this study was to compare the bronchoprotective and bronchodilator effects of a single dose of 12 microg of formoterol from the HFA Modulite inhaler with the Foradil Aerolizer (dry powder inhaler, DPI) and the Foradil CFC inhalers (Novartis Health Consumer, Basel, Switzerland). METHODS: This was a double blind, double dummy, randomized, placebo-controlled, crossover study conducted in 38 subjects with mild to moderate asthma (mean forced expiratory volume in 1 s [FEV1] 87.5% predicted). The primary endpoint was methacholine challenge provocative dose required for 20% fall in the FEV1 (PD20) 90 min post dose. Bronchodilation was assessed with spirometry (FEV1, FVC, FEF25-75) and impulse oscillometry (resistance at 5 and 20 Hz, reactance at 5 Hz and resonant frequency) over the 90 min post dose. In a subset of 12 subjects formoterol plasma levels, serum potassium and glucose were determined up to 480 min post dose. RESULTS: The three formoterol formulations demonstrated significant (P < or = 0.05) improvements in bronchoprotection compared to placebo and non-inferiority of the HFA preparation compared to the CFC and DPI preparations was demonstrated. Geometric mean PD20 values were 0.51 mg with HFA, 0.62 mg with DPI, 0.62 mg with CFC and 0.2 mg with placebo. The log transformed mean differences in PD20 doubling dose between HFA and (a) DPI was -0.28 (95% CI -0.84-0.29, P = 0.57) (b) CFC was -0.28 (95% CI -0.84-0.28, P = 0.57) and (c) placebo was 1.38 (95% CI 0.82-1.94, P < 0.001). Serum potassium, glucose and formoterol plasma profiles were comparable for the CFC, HFA and DPI devices. CONCLUSION: Our findings of similar efficacy, pharmacokinetics and systemic effects of the HFA formoterol inhaler compared to the CFC and DPI preparations supports the potential use of this novel formulation in the treatment of asthma.

Administration, Inhalation↗

PubMed2004

Reported versus confirmed wheeze and lung function in early life.

AIMS: To investigate the relation between parentally reported wheeze (unconfirmed), physician confirmed wheeze, and subsequent lung function. METHODS: Children at risk of allergic disease (one parent atopic) were recruited antenatally and followed prospectively from birth. During the first three years of life parents were asked to contact the study team if their child was wheezy. The presence of wheeze was confirmed or not by the primary care or study physician. Respiratory questionnaire and specific airway resistance measurement (sR(aw), body plethysmograph) were completed at age 3 years. RESULTS: A total of 454 children were followed from birth to 3 years of age. One hundred and eighty six (40.9%) of the parents reported their child wheezing in the first three years of life, and in 130 (28.6%) the wheeze was confirmed. A total of 428 children attended the three year clinic review, of whom 274 (64%) successfully carried out lung function tests. There was no significant difference in sR(aw) (kPa.s; geometric mean, 95% CI) between children who had never wheezed (n = 152; 1.03, 1.00 to 1.06) and those with a parentally reported but unconfirmed wheeze (n = 36; 1.02, 0.96 to 1.07, p = 1.00). sR(aw) was significantly higher in children with a physician confirmed wheeze (n = 86; 1.17, 1.11 to 1.22, p < 0.001) compared to those with no history of wheeze or with unconfirmed wheeze. CONCLUSIONS: Children with physician confirmed wheeze have significantly poorer lung function compared to those with parentally reported but unconfirmed and those who have never wheezed. A proportion of parents may have little understanding of what medical professionals mean by the term "wheeze".

Analysis of Variance↗

PubMed2003

Skin test reactivity to natural and recombinant Blomia and Dermatophagoides spp. allergens among mite allergic patients in the UK.

BACKGROUND: Many asthmatics in tropical and subtropical areas have positive skin prick tests to both Dermatophagoides spp. and to the mite Blomia tropicalis. This may be due to recognition by IgE of cross-reactive allergens between the different mite species or because of sensitization to species-specific allergens. A 14-kDa Blomia tropicalis allergen, Blo t 5, has been cloned and shows 40% sequence homology with Der p 5. The aim of this study was to investigate reactivity to B. tropicalis in patients known to be sensitized to D. pteronyssinus and to assess allergenic activity and cross-reactivity of recombinant (r) Group 5 allergens amongst these patients, who live in the UK and who are not exposed to B. tropicalis in their homes. METHODS: Patients (n = 19) with asthma and/or rhinitis were selected based on clinical history and a positive skin prick test to D. pteronyssinus extract and were compared with non-allergic skin test negative controls (n = 10). IgE antibody responses to Blomia tropicalis, Dermatophagoides pteronyssinus, rDer p 5 and rBlo t 5 were compared by quantitative intradermal skin testing using serial 10-fold dilutions of each allergen. End point titre was the highest dilution giving an 8 x 8 mm wheal at 15 min. IgE antibodies to Blomia tropicalis, Dermatophagoides pteronyssinus, rDer p 5 and rBlo t 5 were measured using RAST, CAP and RIA, respectively. RESULTS: All 19 patients had positive skin tests to D. pteronyssinus at concentrations of 0.001 to 1 AU/ml and 10 were skin test positive to rDer p 5 at concentrations of 10-4 to 5 micro g/ml. Positive intradermal tests to Blomia tropicalis were seen in 12/19 patients at concentrations of 0.002 to 2 micro g/ml. However none of the patients had positive skin tests to rBlo t 5. Non-allergic controls were all skin test negative at the highest concentration of each allergen tested. All subjects had quantifiable specific IgE to D. pteronyssinus, but only two had IgE to B. tropicalis. IgE to Der p 5 was found in six patients, but no patients had IgE to Blo t 5. CONCLUSIONS: This study of patients naturally exposed to D. pteronyssinus but not to Blomia tropicalis, provides evidence for IgE mediated cross-reactivity between allergens produced by both mite species. The results suggest that the Group 5 allergens of D. pteronyssinus and B. tropicalis are species-specific.

Adult↗

PubMed2003

Air filtration units in homes with cats: can they reduce personal exposure to cat allergen?

BACKGROUND: Domestic air filtration units have previously been shown to cause a dramatic fall in airborne pet allergen levels in homes with pets. Clinical trials of air filtration units, however, have failed to reveal a significant beneficial effect. Personal pet allergen exposure during air filtration unit use has never been measured. OBJECTIVE: To determine the effect of air filtration on inhaled cat allergen exposure in homes with cats. METHODS: Nasal air samplers were worn to measure personal cat allergen exposure. The study was carried out in five homes with cats on 4 separate days examining four experimental conditions (cat absent or present, air filtration off or on). The two operators collected four baseline samples and two 15-min samples/h over three consecutive hours. Cat allergen-bearing particles were detected by immunoblotting and allergen concentrations measured by amplified enzyme-linked immunosorbent assay (ELISA). RESULTS: There was a significant reduction in the quantity of the inhaled Fel d 1 when the air cleaner was used with the cat in the room. Fel d 1 halo counts (detransformed means) were 29.3 at baseline, 11.8 after 1 h, 10.0 after 2 h and 14.1 after 3 h, with no change on control days (P = 1.00). With the cat elsewhere in the house, a marginal, but statistically significant reduction was observed only after 3 h with the use of air cleaner (Fel d 1 halo count: baseline 12.4; 3 h 5.5; P = 0.01). CONCLUSIONS: The use of air filtration units appears to result in a much smaller reduction of inhaled cat allergen exposure than suggested by previous studies using standard air samplers. Cat removal remains the best advice to cat-allergic patients who experience symptoms upon exposure.

Air Conditioning↗

PubMed2003

Stringent environmental control in pregnancy and early life: the long-term effects on mite, cat and dog allergen.

BACKGROUND: As part of a primary prevention of asthma study, we measured the effect of environmental control measures on Der p 1, Fel d 1 and Can f 1 over a 3.5-year period. METHODS: High-risk infants (both parents atopic) without pets, were randomized to the Active group (n = 142, vinyl flooring in child's room, allergen-impermeable cot mattress, hot-washable toy, mite allergen-impermeable encasings to parental bed and to child's bed when older, high filtration vacuum cleaner, hot-washing of bedding) or the Control group (n = 136, no intervention), in early pregnancy. Dust samples from the parental mattress, living room floor, child's mattress and floor at baseline (pregnancy), birth and at 3 years were analysed for Der p 1, Fel d 1 and Can f 1. RESULTS: A total of 278 families completed the baseline visit, 259 the birth visit and 239 the 3-year visit. In the Active group at 3 years, 58% remained compliant with all measures likely to reduce the child's exposure to allergen and 77% of parents still used encasings on their bed. Levels of Der p 1, Fel d 1 and Can f 1 were significantly lower in the Active group in the child's floor and the child's mattress at 3 years compared to the Control group (P < 0.001). For the parental mattress, the levels of Der p 1 and Fel d 1 were lower in the Active group (P < 0.001) and there was a strong trend towards a lower level for Can f 1. There was no difference in the levels of any of the allergens between the groups in the living room floor. Childrens' bedrooms with no detectable mite, cat or dog allergen were significantly more common in the Active than the Control group (25 vs. 2, P < 0.001). CONCLUSIONS: Environmental control measures are effective in substantially reducing levels of Der p 1, Fel d 1 and Can f 1 in homes without pets in the long term and are acceptable to families. The effect of this environmental manipulation on the development of sensitization and allergic disease remains to be seen.

Adult↗