Endotoxin, cat, and house dust mite allergens in electrostatic cloths and bedroom dust.

Environmental exposure to endotoxin, Fel d I (cat) allergen and Der p I (house dust mite) allergen have been associated with asthma symptoms and have been measured in the environment using various sampling methods, including the electrostatic dust collector. The objectives of this study were to investigate whether levels of endotoxin and allergens were detectable in electrostatic dust collectors and to examine the correlation of allergen and endotoxin levels between electrostatic dust collectors and vacuum sampling methods (floor dust and mattress dust). Electrostatic cloths, bedroom floor dust and mattress dust samples from a subset of 60 homes were randomly selected from the Health of Occupants of Mouldy Homes study for allergen and endotoxin analysis. Fel d I and Der p I allergens were analyzed by double monoclonal antibody ELISA and endotoxin by the kinetic Limulus amoebocyte lysate assay. An enhanced ELISA method was used to analyze Der p I in the electrostatic cloths. Endotoxin was detected in all samples, however Fel d I and Der p I were not detected in all electrostatic dust collector samples (detection in 53% and 15% of cloths respectively). No correlations were found between cloth and dust samples for endotoxin or Der p I, but moderate-to-strong correlations were found between all three sampling methods for Fel d I (rs = 0.612-0.715, p < 0.001). Poor correlation was found between floor dust and mattress dust samples for Der p I (rs = 0.256, p = 0.048). Electrostatic dust collectors may provide a way to measure airborne dust and allergen. Given the moderate-to-low correlations with vacuum dust sampling, this may present a unique measurement system which, when collected alongside traditional vacuum dust sampling, could provide additional exposure measures. Further studies are required to correlate endotoxin and allergen levels measured by electrostatic dust collector with air sampling and to explore the relationships between these bioaerosols, environmental factors and asthma.

Randomized controlled trial of the effect of regular paracetamol on influenza infection.

BACKGROUND AND OBJECTIVE: Anti-pyretic treatment is recommended in the management of influenza infection. In animal models anti-pyretic treatment increases mortality from influenza. We investigated the effects of paracetamol on viral and clinical outcomes in adults with influenza infection. METHODS: This is a randomized, double-blind, placebo-controlled trial of adults aged 18-65 years with influenza-like illness and positive influenza rapid antigen test. Treatments were 1 g paracetamol four times a day, or matching placebo, for 5 days. Pernasal swabs were taken for influenza quantitative RT-PCR at Baseline and Days 1, 2 and 5. Temperature and symptom scores were recorded for 5-14 days or time of resolution respectively. The primary outcome variable was area under the curve (AUC) for quantitative PCR log10 viral load from Baseline to Day 5. RESULTS: A total of 80 participants were randomized: no one was lost to follow up, and one withdrew after 4 days. There were 22 and 24 participants who were influenza PCR-positive in placebo and in paracetamol groups respectively. Mean (SD) AUC PCR log10 viral load was 4.40 (0.91) in placebo and 4.64 (0.88) in paracetamol; difference was -0.24, 95% CI: -0.78 to 0.29, P = 0.36. In all participants there were no differences in symptom scores, temperature, time to resolution of illness and health status, with no interaction between randomized treatment and whether influenza was detected by PCR. CONCLUSION: Regular paracetamol had no effect on viral shedding, temperature or clinical symptoms in patients with PCR-confirmed influenza. There remains an insufficient evidence base for paracetamol use in influenza infection. CLINICAL TRIAL REGISTRATION: ACTRN12611000497909 at the Australian New Zealand Clinical Trials Registry.

Effect of repeated freeze/thawing of household dust extracts on ß-(1,3)-glucan levels.

ß-(1,3)-glucan exposure from household dust has been shown to be associated with respiratory symptoms and thus is increasingly being measured in epidemiological studies. Various factors are known to influence its measurement; however, no studies have assessed the effects of sample extract freeze-thawing on ß-(1,3)-glucan. The aim of this study was to assess the effects of repeated freeze-thawing of household dust extracts on levels of ß-(1,3)-glucan. Forty random household dust samples were extracted with 0.3 M NaOH and aliquots of extracts stored at -20 °C were subjected to one, two, and three freeze-thaw cycles. They were analyzed for ß-(1,3)-glucan by the Limulus amoebocyte assay (LAL) and results compared to freshly extracted samples (paired Pearson's t-test on logged values). Initial freezing of house dust extracts results in a significant decline in ß-(1,3)-glucan. However, repeated freeze/thawing (up to three times) does not results in any further decline in ß-(1,3)-glucan levels.

Asthma, atopy and exhaled nitric oxide in a cohort of 6-yr-old New Zealand children.

BACKGROUND: Exhaled nitric oxide has been promoted as a non-invasive measure of airway inflammation, with clinical utility for the diagnosis and management of asthma. AIM: We studied associations between exhaled nitric oxide, asthma and atopy in a variety of clinically relevant phenotypes in a cohort of 6-yr-old children. METHOD: Asthma was defined using standard questionnaire criteria, atopy was measured using skin prick tests (SPT) and specific IgE to common allergens, and exhaled nitric oxide was measured using a chemiluminescence analyser according to American and European Thoracic Society criteria. RESULTS: Exhaled nitric oxide was strongly related to atopy and in particular to sensitization to house dust mites. Children with non-allergic asthma had no increase in exhaled nitric oxide compared with non-asthmatic children. Compared with children who never wheezed both late onset and persistent, wheezing was associated with increased FE(NO), while early transient wheezing was not. Elevated levels of exhaled nitric oxide amongst children with allergic asthma were almost entirely explained by their levels of specific IgE to aeroallergens, predominantly D pteronyssinus. CONCLUSION: Airway inflammation as measured by exhaled nitric oxide in young New Zealand children is related to their level of specific IgE to aeroallergens. This has implications for the utility of nitric oxide as a diagnostic and management tool in childhood asthma and for the importance of specific IgE as a marker of asthma severity.

Daily vacuuming of mattresses significantly reduces house dust mite allergens, bacterial endotoxin, and fungal ß-glucan.

BACKGROUND AND AIMS: Atopic patients are advised to cover their mattresses with occlusive coverings; however, these are not cheap. We investigated whether daily vacuum cleaning of mattresses significantly reduces content of house dust mite allergens, bacterial endotoxin, and fungal ß-glucan. METHODS: Twenty volunteers vacuumed their mattress daily for 8 weeks. Dust samples collected at two weekly intervals were analyzed for house dust mite allergens (Der p 1 and Der f 1) by double monoclonal antibody ELISA and for endotoxin and ß-glucan by the Limulus amoebocyte lysate kinetic assay. Results are presented as geometric means with 95% confidence interval (CI). RESULTS: Total house dust mite allergens (Der p 1 + Der f 1) significantly reduced from a geometric mean (95% CI) of 4.07 µg (2.44-6.79) at the start to 0.42 µg (0.21-0.81) at week 8. Total endotoxin and ß-glucan were also significantly reduced from 13.6 EU (8.6-21.4) to 3.4 EU (2.3-5.0) and from 94.4 µg (57.1-156.2) to 19.7 µg (10.2-37.9), respectively (p for trend >.0001). Percentage reductions in total house dust mite allergens, endotoxin, and ß-glucan after 8 weeks of daily vacuum cleaning were 85.1% (80.1-90.1), 71.0% (70.4-81.0), and 75.7% (70.4-81.0), respectively. This was mainly due to a 77.7% (70.8-84.7) reduction in total dust. CONCLUSION: Daily vacuum cleaning of mattresses over time significantly reduces house dust mite allergens, endotoxin, and ß-glucan. This gives atopic patients a practical and cheaper alternative to reduce their exposure to indoor house dust mite allergens and microbial bio-contaminants.

Incidence of percutaneous injuries and non-reporting rates among first-aid responders in Taiwan.

We determined the incidence of percutaneous (needlestick and sharps) injuries among emergency medical technicians (EMTs) in one county in Taiwan, compared this with the official reporting rate, and sought reasons for non-reporting. An anonymous questionnaire was distributed to all EMTs in that county, eliciting percutaneous injuries occurrences, reasons why, and reporting data. Data were analyzed by logistic regression. A total of 329 out of 353 EMTs completed the questionnaire, giving a response rate of 93.2%. Thirty-nine EMTs (11.9%) experienced at least one percutaneous injury in the preceding 12 months. Older, less experienced EMTs were at greater risk of percutaneous injuries. None of the EMTs officially reported their percutaneous injuries primarily because they thought reporting was not mandatory and that the reporting process was too complicated. About one in eight EMTs had experienced at least one percutaneous injury in the preceding year. None of these injuries was officially reported to their organization. Ways to make reporting more user friendly are required, along with resources to minimize percutaneous injuries among EMTs in Taiwan.

A pilot study of nicotine delivery to smokers from a metered-dose inhaler.

INTRODUCTION: The present study generated preliminary data on the acceptability and pharmacokinetics of nicotine administered by a simple metered-dose inhaler (MDI). METHODS: We conducted a nonrandomized, open-label cross-over trial of 10 current smokers. On Day 1, a single cigarette was smoked ad libitum. On Day 2, participants took 10 puffs (20 inhalations) of 50 microg nicotine/puff through the inhaler, and on Day 3, they took 10 puffs (20 inhalations) of 100 microg nicotine/puff, each over 5 min. Nicotine pharmacokinetics, changes in heart rate and blood pressure, and the acceptability of the inhalers were measured and recorded. RESULTS: Nicotine administered by an MDI produced a median maximum plasma concentration that was about 50% of that obtained by smoking a cigarette (12.5 vs. 25.9 ng/ml) and took twice the time to reach that concentration, 6 versus 3 min. Self-rated satisfaction and reduced urge to smoke were similar for the MDIs and a cigarette. DISCUSSION: The results suggest that nicotine can be delivered effectively by the pulmonary route using a standard MDI. The inhaler appears to provide a satisfaction level and reduction in the urge to smoke relatively similar to that provided by smoking a cigarette. These conclusions require verification in a larger controlled study.

Beta-(1,3)-glucan levels and its determinants in New Zealand bedrooms.

Beta-(1,3)-glucan is a pro-inflammatory component of the fungal cell wall, indoor levels of which have only been considered in a few studies. This study assessed levels of beta-(1,3)-glucan in 35 domestic bedrooms. beta-(1,3)-glucan levels were estimated using a modified Limulus amoebocyte lysate kinetic assay. beta-(1,3)-glucan geometric mean levels (95% confidence interval) were 163.9 microg/g (129.5-209.3) from bedroom floors; 76,6 microg/g (61.4-94.0) from mattresses; 132.1 microg/g (68.9-207.9) from duvets; and 110.0 microg/g (82.2-146.4) from pillows. Synthetic bedding and older mattresses contained higher beta-(1,3)-glucan levels. Synthetic bedding contains higher levels of beta-(1,3)-glucan than feather bedding, which may be of importance to asthmatics.

Indoor allergens and microbial bio-contaminants in homes of asthmatic children in central Taiwan.

Indoor allergens and microbial bio-contaminants play a significant role in asthma symptoms. The aim of the study was to determine levels of house dust mite allergens, bacterial endotoxin, and fungal beta-glucan in homes of 120 asthmatic children in central Taiwan. Dust samples from 120 mattresses (67 double-sided) were analyzed for house dust mite allergens (Der p 1, Der f 1, and Blo t 5), endotoxin, and beta-glucan. Pillows (n = 118) were analyzed for house dust mite allergens only. Kitchen dust samples were analyzed for the cockroach allergen, Bla g 1. Blo t 5 was detected in 9.3% pillows and 82.2% mattresses, Der p 1 in 95.8% pillows and 93.2% mattresses, and Der f 1 in 82.2% pillows and 83.1% mattresses. Geometric mean levels (95% confidence interval) of endotoxin and beta-glucan in mattresses were 108.4 Eu/mg (81.4-144.2) and 25.2 microg/g (22.7-28.0), respectively. House dust mite allergens and endotoxin levels were significantly lower on the bamboo side of 67 mattresses, compared to the inner sprung mattress side. Geometric mean of kitchen Bla g 1 was 0.61 U/g (95% CI: 0.43-0.85). Given the presence of Der p 1, Der f 1 and Blo t 5 in central Taiwan, it is advised to measure allergens of all three house dust mite species to obtain a true index of allergen exposure. Bamboo sides of mattresses had significantly lower house dust mite allergens and endotoxin levels.

Allergies in Animals and Humans.

Allergy to inhalant and food allergens affects many patients worldwide [...].

Effect of Betel (Areca) Nut Chewing on Fractional Exhaled Nitric Oxide: A Pilot Study.

Betel (areca) nuts are extensively chewed in many countries. This has been associated with respiratory symptoms. We aimed to determine whether betel nut chewing is associated with acute changes in fractional exhaled nitric oxide, a non-invasive marker of airway inflammation. Betel nut chewing resulted in an immediate significant decline in fractional exhaled nitric oxide levels that persisted for up to 180 minutes. This effect has to be taken into account in epidemiological studies, reference ranges, and patient preparation.

Upper body clothing is a source of fungal beta-(1,3)-glucan exposure.

Beta-(1,3)-glucan is pro-inflammatory and has been associated with airway inflammation and respiratory symptoms. This study assessed beta-(1,3)-glucan levels from upper body clothing (jerseys) of 55 subjects. Beta-(1,3)-glucan levels were estimated with a modified Limulusamoebocyte lysate kinetic assay. Beta-(1,3)-glucan levels ranged widely from 2,697 to 162,690 ng/g. Beta-(1,3)-glucan levels were significantly lower from cotton jerseys and from warm water washed jerseys. Thus, jerseys are potentially a significant exposure source of beta-(1,3)-glucan.

Prevalence of mouse allergen (Mus m 1) in homes of New Zealand rural children.

Mouse allergen has emerged as an under recognized indoor allergen associated with sensitization and contributing to asthma severity. As part of a study of farm residence, exposures, and risk of allergic diseases in children in New Zealand, 216 living room floor dust samples were analysed for the mouse allergen, Mus m 1. Associations between Mus m 1 and allergic diseases, farm residence, and presence of cats were analysed. Significantly higher levels of Mus m 1 were found in farm dwellings, while the presence of cats was associated with significantly lower Mus m 1 levels. Levels of Mus m 1 in New Zealand were considerably lower than those reported overseas. No significant associations were found between Mus m 1 levels and atopic status or allergic diseases. Mouse allergen is unlikely to be an important indoor allergen for rural New Zealand children.

The effect of 1g of acetaminophen twice daily for 12 weeks on alanine transaminase levels--A randomized placebo-controlled trial.

OBJECTIVE: Acetaminophen is often used on a regular, daily basis for the treatment of chronic pain; however, the safety of regular acetaminophen is still debated. This study determined whether 12 weeks of treatment with acetaminophen at half the maximum recommended daily dose causes an increase in alanine transaminase (ALT) in healthy adults participating in a clinical trial of the effect of acetaminophen on asthma control and severity. DESIGN AND METHODS: 94 healthy adults aged 18-65 years with mild to moderate asthma and with no history of previous liver dysfunction and an ALT within 1.5 times the upper limit of normal at baseline participated in a randomized, double-blind, placebo-controlled, parallel-group, clinical trial of 1g of acetaminophen twice daily or placebo twice daily for 12 weeks. Liver function monitoring was undertaken at baseline, weeks 2, 4, 6 and 12. The primary outcome variable was mean ALT levels at week 12 compared to baseline in the acetaminophen group versus placebo group. RESULTS: 94 participants were randomized and commenced study treatment. One participant in each treatment group was withdrawn due to an increase in ALT to greater than three times the upper limit of normal. Mean ALT at week 12 was 25.4I U/L (SD 9.7) in the acetaminophen group (N=31) and 19.0 IU/L (SD 6.0) in the placebo group (N=54). After controlling for baseline this represented a statistically significant difference of 3.6 IU/L (95% CI 1.3 to 6.0, P=0.003). There was no progressive increase in ALT demonstrated throughout the trial. CONCLUSIONS: Regular, daily use of acetaminophen at half the maximum recommended daily dose for 12 weeks in a healthy adult population is associated with a small elevation in mean ALT of no probable clinical significance. Further assessment of the effects on liver function of the maximum recommended dose of acetaminophen is required.

House dust mite allergen levels in individual bedding components in New Zealand.

AIMS: House dust mite allergen (Der p 1) levels are high in New Zealand and bedding Der p 1 levels have been shown to be associated with the clinical severity of asthma. The aim of this study was to measure Der p 1 levels in synthetic and feather duvets and other individual bedding items, and to examine factors affecting these levels. METHODS: Reservoir dust samples were collected and analysed for Der p 1 content by ELISA from 65 duvets, 81 pillows, and 65 mattresses of 34 children and 31 adults in 34 households. RESULTS: Der p 1 geometric mean levels (95% confidence interval) were: 13.4 microg/g (9.5-18.9) in pillows; 29.4 microg/g (19.8-43.5) in duvets; and 53.8 microg/g (39.4-73.4) in mattresses. Synthetic pillows and duvets yielded significantly more Der p 1 than feather pillows and duvets (about 7-fold and 15-fold respectively). The presence of under-bedding resulted in significantly higher pillow and duvet Der p 1 levels. Mattresses >10 years old had significantly higher Der p 1 levels. CONCLUSIONS: Synthetic pillows and duvets contain higher levels of Der p 1 than feather pillows and duvets. Advise for house dust mite sensitized individuals to use synthetic bedding does not prevent house dust mite allergen exposure.

Randomised placebo-controlled study of the effect of paracetamol on asthma severity in adults.

OBJECTIVE: To investigate the effect of regular paracetamol on bronchial hyper-responsiveness (BHR) and asthma control in adult asthma. SETTING: Single research-based outpatient clinic. PARTICIPANTS: 94 adults with mild-to-moderate asthma received randomised treatment; 85 completed the study. Key inclusion criteria were age 18-65 years, forced expiratory volume in 1 s (FEV1) >70% predicted, provocation concentration of methacholine causing a 20% reduction in FEV1 (PC20) between 0.125 and 16 mg/mL. Key exclusion criteria included an asthma exacerbation within the previous 2 months, current regular use of paracetamol, use of high-dose aspirin or non-steroidal anti-inflammatory drugs, current or past cigarette smoking >10 pack-years. INTERVENTIONS: In a 12-week randomised, double-blind, placebo-controlled, parallel-group study, participants received 12 weeks of 1 g paracetamol twice daily or placebo twice daily. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome variable was BHR, measured as the PC20 at week 12. Secondary outcome variables included FEV1, fractional exhaled nitric oxide (FeNO) and asthma control questionnaire (ACQ) score. RESULTS: At 12 weeks, the mean (SD) logarithm base two PC20 was 1.07 (2.36) in the control group (N=54) and 0.62 (2.09) in the paracetamol group (N=31). After controlling for baseline PC20, the mean difference (paracetamol minus placebo) was -0.48 doubling dose worsening in BHR in the paracetamol group (95% CI -1.28 to 0.32), p=0.24. There were no statistically significant differences (paracetamol minus placebo) in log FeNO (0.09 (95% CI -0.097 to 0.27)), FEV1 (-0.07 L (95% CI -0.15 to 0.01)) or ACQ score (-0.04 (95% CI -0.27 to 0.18)). CONCLUSIONS: There was no significant effect of paracetamol on BHR and asthma control in adults with mild-to-moderate asthma. However, the study findings are limited by low power and the upper confidence limits did not rule out clinically relevant adverse effects. TRIAL REGISTRATION: Australia New Zealand Clinical Trials Registry Number: NZCTR12609000551291.

Effect of Activated Charcoal Fibers on the Survival of the House Dust Mite, Dermatophagoides pteronyssinus: A Pilot Study.

House dust mites produce potent allergens that exacerbate asthma in sensitized patients, whom are recommended to practice allergen avoidance within their home environment. We tested the effect of activated charcoal impregnated fibers on house dust mite survival. One hundred live adult house dust mites (Dermatophagoides pteronyssinus) were added to eight culture dishes preequilibrated at room temperature (n = 4) and 70% humidity (n = 4) containing house dust mite food and active charcoal fibers. At 10 minute intervals, live and dead house dust mites were counted. All house dust mites instantly attached to the activated charcoal fibers and started to shrink almost immediately. There were no live house dust mites present as early as 40 minutes in some dishes while after 190 minutes all house dust mites were dead. In conclusion, activated charcoal fibers, if incorporated into bedding items, have the potential to control house dust mites in the indoor environment.

Do other components of bedding dust affect sensitisation to house dust mites?

Bedding dust is a mixture of many components, of which the house dust mite (HDM) allergen, Der p 1, is the most allergenic. There has been little work to investigate the effect of other bedding dust components on HDM sensitisation. The objective of the study was to determine the effect of endotoxin in bedding dust on the allergic response in HDM-sensitised individuals. Twenty-nine house dust mite-sensitised adults were skin prick and allergen patch tested against a sterile solution of their own bedding dust and against a solution containing the same concentration of Der p 1 as the bedding solution for comparison. There was no significant difference in wheal size between the diluted house dust mite solution and the bedding dust in spite of their high levels of endotoxin. Symptomatic subjects had larger, but not statistically significant, responses to commercial house dust mite solution than asymptomatic subjects. Allergen patch test responses were negative in 22/29 of subjects using either bedding dust solutions or comparable diluted house dust mite solutions. An individual's own bedding dust does not appear to contain factors that enhance skin prick test or atopy patch test responses to house dust mites.