Wellington Asthma Research Group, School of Medicine & Health Sciences, University of Otago, Wellington PO Box 7343, Wellington South 6242, New Zealand
rob.siebers@otago.ac.nz
Robert Siebers trained as a medical laboratory scientist and currently is Research Associate Professor at the School of Medicine & Health Sciences, University of Otago, Wellington, New Zealand. He is a Fellow of the New Zealand Institute of Medical Laboratory Science, Fellow of the New Zealand Institute of Chemistry and Fellow of the Society of Biology, London. His current research interests are indoor allergens and microbial contaminants and its relation to asthma and allergic diseases. He has been the Editor of the New Zealand of Medical Laboratory Science since 1994 and is an Editorial Board Member of the Australian Journal of Medical Science and The International Journal of Occupational and Environment Medicine. He is Board Director of the World Association of Medical Editors (www.wame.org) and is Chair of its Small Journal Taskforce.
Abstract: 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 mug nicotine/puff through the inhaler, and on Day 3, they took 10 puffs (20 inhalations) of 100 mug 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.
Abstract: 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.
Abstract: AIM: Complimentary and alternative medicines are widely used but are not registered medicines. The aim of the study was to compare advice given by health food stores and pharmacists for hypertension. METHODS: Twenty-six health food stores and 26 pharmacies were visited by an individual for advise on a hypothetical problem of hypertension. RESULTS: Staff in 25 out of 26 health food stores did not refer the researcher to a medical practitioner; instead they recommended and sold a wide variety of compounds of unproven efficacy. CONCLUSIONS: We recommend the implementation of a formal training programme for health food stores staff and that complimentary and alternative medicines-use in New Zealand is regulated.
Abstract: 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.
Abstract: BACKGROUND: Several studies have consistently reported inverse associations between exposure to endotoxin in house dust and atopy. With regard to the association between house dust endotoxin and asthma, the results are inconsistent. OBJECTIVES: To study the association between house dust endotoxin levels and respiratory symptoms and atopy in populations from largely different countries. METHODS: Data were collected within the International Study on Asthma and Allergies in Childhood Phase Two, a multi-centre cross-sectional study of 840 children aged 9-12 years from six centres in the five countries of Albania, Italy, New Zealand, Sweden and the United Kingdom. Living room floor dust was collected and analysed for endotoxin. Health end-points and demographics were assessed by standardized questionnaires. Atopy was assessed by measurements of allergen-specific IgE against a panel of inhalant allergens. Associations between house dust endotoxin and health outcomes were analysed by logistic regression. Odds ratios (ORs) were presented for an overall interquartile range increase in exposure. RESULTS: Many associations between house dust endotoxin in living room floor dust and health outcomes varied between countries. Combined across countries, endotoxin levels were inversely associated with asthma ever [adjusted OR (95% confidence interval (CI)) 0.53 (0.29-0.96) for endotoxin levels per m(2) of living room floor] and current wheeze [adjusted OR (95% CI) 0.77 (0.64-0.93) for endotoxin levels per gram of living room floor dust]. There were inverse associations between endotoxin concentrations and atopy, which were statistically significant in unadjusted analyses, but not after adjustment for gender, parental allergies, cat and house dust mite allergens. No associations were found with dust quantity and between endotoxin exposure and hayfever. CONCLUSION: These findings suggest an inverse association between endotoxin levels in living room floor dust and asthma in children.
Abstract: BACKGROUND: This study explored the effects of maternal probiotic supplementation on immune markers in cord blood (CB) and breast milk. METHODS: CB plasma and breast milk samples were collected from a cohort of women who had received daily supplements of either 6 x 10(9) CFU/day Lactobacillus rhamnosus HN001 (n=34), 9 x 10(9) CFU/day Bifidobacterium lactis HN019 (n=35) or a placebo (n=36) beginning 2-5 weeks before delivery and continuing for 6 months in lactating women. CB plasma and breast milk (collected at 3-7 days, 3 months and 6 months postpartum) were assayed for cytokines (IL-13, IFN-gamma, IL-6, TNF-alpha, IL-10, TGF-beta1) and sCD14. Breast milk samples were also assayed for total IgA. RESULTS: Neonates of mothers who received a probiotic had higher CB IFN-gamma levels (P=0.026), and a higher proportion had detectable blood IFN-gamma levels, compared with the placebo group (P=0.034), although levels were undetectable in many infants. While this pattern was evident for both probiotics, when examined separately only the L. rhamnosus HN001 group showed statistically significant higher IFN-gamma levels (P=0.030) compared with the placebo group. TGF-beta1 levels were higher in early breast milk (week 1) from the probiotic groups (P=0.028). This was evident for the B. lactis HN019 group (P=0.041) with a parallel trend in the L. rhamnosus HN001 group (P=0.075). Similar patterns were seen for breast milk IgA, which was more readily detected in breast milk from both the B. lactis HN019 (P=0.008) and the L. rhamnosus HN001 group (P=0.011). Neonatal plasma sCD14 levels were lower in the B. lactis HN019 group compared with the placebo group (P=0.041). CONCLUSION: The findings suggest that supplementation with probiotics in pregnancy has the potential to influence fetal immune parameters as well as immunomodulatory factors in breast milk.
Abstract: House dust mites produce inhalant allergens of importance to allergic patients. We measured the major group 1 allergens, Der p 1 and Der f 1, from the house dust mites Dermatophagoides pteronyssinus and Dermatophagoides farina, respectively in 100 randomly selected domestic homes from Cheonan, Korea. Dust samples were collected by vacuuming from the living room floor and 1 mattress in each home. Der p 1 and Der f 1 were measured by double monoclonal ELISA. Der p 1 levels were very low, with geometric mean levels for floors and mattresses being 0.11 microgram/g (range: 0.01-4.05) and 0.14 microgram/g (range: 0.01-30.0), respectively. Corresponding levels of Der f 1 were higher, 7.46 microgram/g (range: 0.01-262.9) and 10.2 microgram/g (range: 0.01-230.9) for floors and mattresses, respectively. D. farinae appears to be the dominant house dust mite in Cheonan.
Abstract: BACKGROUND: In general, studies reporting positive associations between antibiotic exposure and respiratory and allergic disease have been unable to determine the nature of this association. OBJECTIVE: To examine the association between antibiotic exposure in infancy and the development of asthma, eczema and atopy in early childhood. METHODS: In a birth cohort study, we collected reported antibiotic exposure before 3 months and before 15 months along with outcomes (wheeze, asthma, eczema, rash, inhaler use) at 15 months (n=1011) and 4 years (n=986). Atopy was measured using skin prick tests at 15 months. RESULTS: We found significant univariate associations of antibiotic exposure before 3 months with asthma developing between birth and 15 months [OR 2.32 (95% CI 1.45-3.69)]. After adjustment for chest infections, this association reduced (OR=1.58, 95% CI 0.96-2.60) becoming marginally significant (P=0.07). A marginally significant association of antibiotics with atopy (OR=1.44, 95% CI 0.96-2.14) in the univariate analysis also reduced after adjustment for chest infections (OR=1.36, 95% CI 0.91-2.05). There was no effect of antibiotic exposure before 15 months on asthma developing after 15 months and present between 3 and 4 years (OR=1.35 95% CI 0.85-2.14). Antibiotic exposure before 3 months was not associated with eczema and rash developing between birth and 15 months but exposure before 15 months was related to eczema [OR 1.83 (95% CI 1.10-3.05)] and rash [OR 1.61 (95% CI 1.02-2.53)] developing after 15 months and remaining present at 4 years. These effects reduced in the multivariate analysis. CONCLUSIONS: Our findings suggest that the effect of antibiotics on respiratory disease may be due to confounding by chest infections at an early age when asthma may be indistinguishable from infection.
Abstract: BACKGROUND: Asthma and allergy are highly prevalent in industrialised countries. Longitudinal and cross-sectional studies have identified a number of potential risk factors for these conditions, including genetic and environmental factors, with significant gene-environment relationships. Birth cohort studies have been proposed as an important tool to explore these risk factors, particularly exposures in early life that are associated with later disease or protection from disease. This paper describes the establishment of a birth cohort in New Zealand. METHODS: A birth cohort was established in 1996 in Christchurch and Wellington and infants recruited between 1997-2001. Expectant mothers were recruited by midwives. Children and mothers have undergone assessment by serial questionnaires, environmental assessment including mould and allergen exposure, skin-prick testing, and at age six years are undergoing full assessment for the presence of asthma, atopy and allergic disease, including genetic assessment. RESULTS: A total of 1105 children have been recruited, and the retention rate at fifteen months was 91.4%. 15.2% of the children at recruitment have been identified as Maori. A positive family history of asthma, eczema or hay fever has been reported in 84% of children. All children have now been assessed at fifteen months and 685 children from the cohort have reached age six years and have completed the six year assessment. CONCLUSIONS: The cohort is fully assembled, and assessment of children is well advanced, with good retention rates. The study is well placed to address many current hypotheses about the risk factors for allergic disease and asthma.
Abstract: 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.
Abstract: AIMS: A large majority of children in New Zealand attend daycare centres and kindergartens early in life. Overseas studies have demonstrated a possible protective effect of daycare attendance against asthma and allergy later in life. One hypothesised agent for this protection is high levels of endotoxin, which have not previously been measured in New Zealand childcare facilities. The purpose of this study was to measure endotoxin and indoor allergens in kindergartens and daycare centres in the Wellington region. METHODS: Dust samples were collected from 18 kindergartens and 18 daycare centres and analysed for endotoxin by the kinetic limulus amebocyte lysate assay and for indoor allergens by double monoclonal/polyclonal antibody ELISA. RESULTS: The geometric mean level (95% CI) was 29,206 EU/g (19,410-43,950) for endotoxin, 0.25 mcg/g (0.04-2.28) for Der p 1, 1.24 mcg/g (0.80-1.90) for Fel d 1, 0.43 mcg/g (0.26-0.71) for Can f 1, and 0.028 mcg/g (0.020-0.039) for Bla g 2. CONCLUSIONS: Endotoxin levels in daycare centres and kindergartens in Wellington, New Zealand are similar to domestic dwellings in Wellington, however indoor allergen levels are much lower. The low indoor allergens in the daycare centres and kindergartens are unlikely to be problematic for sensitised infants, although some individual childcare facilities had very high Der p 1 levels.
Abstract: House dust mite sensitized asthmatics are advised to practice allergen avoidance. Charcoal pillows are used in Korea with unsubstantiated claims regarding their efficacy in alleviating asthma symptoms. We tested the effects of activated charcoal on breeding of house dust mites in culture. Twenty live adult house dust mites (Dermatophagoides pteronyssinus) were inoculated, 10 replicates, on culture media containing 0%, 1%, 3%, 5%, 10%, and 20% activated charcoal and incubated at 25 degrees C and a relative humidity of 75%. After four weeks, the mean numbers of live house dust mites were 286, 176, 46, 16, 7, and 0 for the 0%, 1%, 3%, 5%, 10%, and 20% charcoal-containing culture media, respectively. Thus, activated charcoal suppresses breeding of house dust mites and offers a new promising method for house dust mite control.
Abstract: 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.
Abstract: Bacterial endotoxin, fungal (1 --> 3)-beta-D-glucans, and extracellular polysaccharides from Aspergillus and Penicillium (EPS-Asp/Pen) have been suggested to be stable markers of microbial exposure. This paper describes a pilot study in which we measured endotoxin, (1 --> 3)-beta-D-glucans, EPS-Asp/Pen and mite allergen in house dust collected in 32 homes in Wellington, New Zealand. Endotoxin (GM 60,295 EU/g; GSD 2.4) and glucan (GM 2,687 microg/g; GSD 1.5) levels were higher in comparison to previous international studies, whereas EPS-Asp/Pen levels (37,347 Units/g; GSD 1.9) appeared comparable. Concentrations expressed per square meter were highly correlated among the measured components (p < 0.05). When expressed per gram of dust only (1 --> 3)- beta -D-glucans and EPS-Asp/Pen were correlated (r=0.55, p < 0.01; n=32). Endotoxin and glucan levels were higher (borderline statistically significant; p < 0.10) in homes with self-reported water damage. A positive association (p < 0.10) was also found for dust mite and a combination of self-reported mould, dampness and water damage. EPS levels were higher in homes where residents indicated the presence of mould spots on the wall, but this did not reach statistical significance. In conclusion, levels of microbial contaminants in a small random sample of New Zealand homes were high and weakly associated with water damage.
Abstract: BACKGROUND: Wheezing in infancy is common and is associated with small lungs, viral respiratory tract infection, and environmental tobacco smoke exposure. Recently, increased levels of endotoxin in the domestic environment have also been associated with infant wheezing, particularly among infants with a family history of atopic disease. OBJECTIVE: To explore associations between exposure to endotoxin at 3 months of age and reported symptoms of wheezing, rhinitis, itchy scaly rash, and atopy at 15 months in a birth cohort of 881 New Zealand children. METHODS: Using standardized methods, a 1-m(2) site from the bedroom floors of the 3-month-old infants was sampled and analyzed for endotoxin. RESULTS: Wheezing was significantly associated with higher endotoxin levels (odds ratio [OR], 1.54; 95% CI, 1.03-2.30), particularly among infants with a parental history of allergic disease (OR, 1.67; 95% CI, 1.07-2.60). Higher endotoxin concentrations were also strongly associated with recurrent itchy rashes (OR, 1.87; 95% CI, 1.14-3.05), particularly among infants who were atopic (OR, 4.64; 95% CI, 1.56-13.77) or had a parental history of allergic disease (OR, 2.10; 95% CI, 1.22-3.61). CONCLUSION: Domestic endotoxin was associated with reported airway and skin symptoms in this large group of New Zealand infants. The role of endotoxin in the development of respiratory and skin disease in infancy deserves further study. CLINICAL IMPLICATIONS: Reducing domestic endotoxin exposure might reduce infant wheezing and atopic dermatitis, but the long-term benefits of this remain unclear.
Abstract: BACKGROUND: Recent evidence has suggested that high exposure to cat allergens is associated with decreased prevalence of sensitization to cat and, in some studies, decreased asthma. OBJECTIVE: Our objective was to study antibodies to cat and mite allergens and their relationship to wheezing in a country with high exposure to both allergens. METHODS: Sera from 112 wheezing and 112 control children aged 10 to 11 years in a nested case-control study in New Zealand were assayed for specific IgE antibody, as well as IgG antibody and IgG4 antibody, to Der p 1 and Fel d 1. RESULTS: IgE antibody to both mite (99/224) and cat (41/224) were strongly associated with wheezing (odds ratios, 5.2 and 6.5, respectively). Children who had ever lived with a cat were less likely to have IgE antibody to cat (20/141 vs 21/83, P < .04); however, cat ownership had no effect on IgE antibody to mite (67/141 vs 32/83, P = .23). Among sensitized children, cat ownership was associated with a lower prevalence of IgE antibody to cat (28% vs 66%, P < .001), and this analysis remained significant after exclusion of children whose families had chosen not to own a cat. Among sensitized subjects, the mean titer of IgE antibody to cat (1.7 IU/mL) was 10-fold lower than for mite (22.1 IU/mL). A cat in the home had no significant effect on endotoxin or mite allergen in house dust, whereas cat allergen was much higher (40.8 vs 3.3 microg/g). CONCLUSION: The response to these 2 allergens was distinct on the basis of the prevalence of sensitization, the titer of IgE antibody, and the effect of cat ownership. The results suggest that induction of tolerance to cat allergen is an allergen-specific phenomenon that cannot be attributed to endotoxin or family choice. The strength of the IgE antibody response to dust mite in humid climates could contribute to the increased prevalence and severity of asthma.
Abstract: BACKGROUND: Previous studies have shown that children in Tokelau have a lower prevalence of asthma and atopy compared to Tokelauan children resident in New Zealand. We hypothesized that the low asthma and atopy prevalence in Tokelau may be associated with low indoor allergen levels. METHODS: Dust was collected from bedding and floors of 76 homes and four public buildings in Tokelau and from the homes of 30 Tokelauan families in Wellington, New Zealand. Dust samples were analysed for Der p 1, Der f 1, Can f 1, Fel d 1, Bla g 2 and Blo t 5 by ELISA, and for endotoxin by a kinetic amoebocyte lysate assay. RESULTS: Der p 1 levels were over 1000-fold lower in Tokelau compared to New Zealand, geometric mean levels were 0.04 and 47.0 microg/g in beds and 0.04 and 44.7 microg/g on floors, respectively. Can f 1 and Fel d 1 levels were also significantly lower in Tokelau. Bed endotoxin levels were significantly higher in Tokelau, geometric mean: 26 736 EU (endotoxin units)/g, compared to 5181 EU/g in New Zealand. Floor endotoxin levels were similar between the two countries. CONCLUSION: The very low indoor allergen levels in homes in Tokelau compared to much higher levels in New Zealand homes provides a logical explanation for the lower prevalence of asthma and atopy in Tokelau, compared to New Zealand.
Abstract: Many studies have documented nurses' attitudes and concerns regarding AIDS/HIV, but little is known about Taiwanese nurses. We documented attitudes, concerns, gloving practices and practical AIDS/HIV knowledge of 1090 nurses from one metropolitan hospital in Changhua City, Taiwan. The response rate was 80.9%. Both HIV and hepatitis contraction in the workplace was nurses' main concern. Two hundred and ten nurses (19.3%) were seriously considering leaving nursing because of fear of contracting AIDS/HIV. Virtually all nurses considered it their right to be informed of the presence of HIV-positive patients in their direct work area and many believed that HIV testing of patients should be mandatory. Practical AIDS/HIV knowledge was deficient. These Taiwanese nurses have concerns and fears that might be related to deficiencies in practical AIDS/HIV knowledge. Continuous educational programmes are recommended to alleviate these nurses' attitudes and concerns regarding AIDS/HIV.
Abstract: The role that house dust mites play in the primary causation of asthma is controversial. Approximately thirty-six 10-yr-old children in each of 10 centres in the Asia-Pacific region participated. Researchers collected dust from mattresses and living room floors using standardized procedures. Der p1 and Der f1 were analysed using a double monoclonal antibody enzyme-linked immunosorbent assay. Geometric mean allergen levels were calculated for each centre. An ecological analysis was conducted to show the regression of the geometric mean allergen level, using the highest household level, against asthma symptom and severity prevalence data from the International Study of Asthma and Allergies in Childhood, Phase I. Among children aged 13-14 yr, the change in asthma symptom prevalence was associated with per unit change in Der p1 microg/g (1.08, 95% CI 0.10-2.06) and Der 1 microg/g (Der p1 + Der f1) (0.64, 95% CI 0.02-1.26). The change in having four or more attacks of asthma in the last 12 months was associated with per unit change in Der p 1 microg/g (0.29, 95% CI -0.02 to 0.60) and Der 1 microg/g (0.20, 95% CI 0.01-0.38). There was no effect for total Der p1 or Der f1 (total or microg/g). Among children aged 6-7 yr, neither allergen was related to symptoms or severity prevalence. While our findings suggest that Dermatophagoides pteronyssinus may have a role in the primary causation of asthma, the complexity of this association reinforces the need for prospective studies.
Abstract: Variable methods of dust collection may lead to uncertainty in the measurement of biomarkers. The purpose of this study was to examine the effect of two different dust collection devices on dust weight, Der p 1, Fel d 1, and endotoxin levels. We compared: (1) a nylon mesh sock inserted between the furniture attachment and the vacuum hose (the reference method) and (2) the ALK device. Duplicate dust samples were collected for 2 min from 2 m(2) of 37 living room floors and from each longitudinal half of 37 mattresses. Measurement of Der p 1 and Fel d 1 were by double monoclonal antibody enzyme-linked immunosorbent assay (ELISA) and endotoxin by a Limulus Amobocyte Lysate assay. Geometric mean ratios (95% confidence intervals) were calculated to show the differences between sampling devices for each measurement. Compared with the ALK device, the reference method collected significantly more dust from floors (sevenfold) and mattresses (threefold) and more total Der p 1, Fel d 1, and endotoxin in both sites. Floor, but not mattress, Der p 1 concentrations were also significantly higher (threefold) using our reference method. We recommend that, in order to minimize sampling device bias, allergen and endotoxin are expressed as a concentration, and that the bed is considered the major source of allergen exposure. Practical Implications Dust sampling equipment can influence the dust yield. In order to have confidence in comparisons of allergen and endotoxin reservoir levels between centers, standardization in the use of sampling equipment is important.
Abstract: BACKGROUND: Previous studies have demonstrated significantly higher house dust mite (HDM) allergen levels from synthetic pillows, compared to feather pillows. Reasons for these differences could be lower permeability of feather pillow coverings to allergen in dust, greater HDM penetration of synthetic pillow covering, or both. OBJECTIVES: To determine the permeability of synthetic and feather pillow coverings to live HDMs and house dust. METHODS: Twenty live adult HDMs were seeded on top of two types of synthetic pillow covering (one standard polyester and one newer polyester/cotton type) and one type of feather pillow coverings with adequate food supply below in sealed culture dishes, kept at 23 degrees C and 70% relative humidity. After 24 and 48 h live HDM numbers remaining on top of the coverings were enumerated microscopically. Three aliquots of fine house dust (each in triplicate) were placed on top of the synthetic and feather pillow coverings, shaken gently for 30 min and penetrated dust was collected and weighed. RESULTS: After 24 h, all 20 HDMs had penetrated the standard synthetic pillow coverings, and no HDMs had penetrated either the feather pillow or the new synthetic pillow coverings after 24 or 48 h. Dust permeability (% of applied dust) for the standard synthetic, new type synthetic and feather pillow coverings were 0.88%, 0.07%, and 0.07%, respectively. This compared to 0.02% for a commercial occlusive pillow cover. CONCLUSIONS: These findings of total permeability of standard synthetic pillow coverings to live HDMs, and their greater permeability to house dust could explain their reported higher HDM allergen levels, compared to feather pillow coverings. Newer types of synthetic pillow coverings are similar to feather pillow coverings in their permeability to live HDMs and house dust.
Abstract: Pillows are known to contain significant levels of indoor allergens and endotoxin, that are of importance to house dust mite sensitized asthmatics. Buckwheat pillows are commonly used in Korea. We studied the levels of the house dust mite allergen, Der f 1, and endotoxin on new synthetic and buckwheat pillows and their accumulation over three months. Endotoxin levels were significantly higher on new buckwheat pillows compared to synthetic pillows; geometric mean levels (95% CI) were 60,950 EU/g (30,270-122,700) and 4,887 EU/g (2,570-9,311) respectively (p<0.001). No Der f 1 was detected on the new pillows. After three months Der f 1 levels were similar on buckwheat and synthetic pillows, geometric mean levels (95% CI) were 1.16 microg/g (0.02-8.13) and 1.08 microg/g (0.19-1.68) respectively. These results indicate that buckwheat pillows are a source of very high endotoxin levels that may be of relevance to asthma severity of atopic asthmatics.
Abstract: OBJECTIVES: Formoterol, a beta(2) agonist with a rapid onset of effect and long duration of action, can be used as maintenance and reliever medication for asthma and COPD. We compared the pulmonary and extra-pulmonary effects of cumulative doses of formoterol and salbutamol in patients with COPD to assess efficacy and safety. METHODOLOGY: In a randomized, double-blind, cross-over study, 12 patients with moderate to severe COPD inhaled, via Turbuhaler, 10 doses of formoterol (total metered dose, 120 microg, equivalent to a 90- microg delivered dose), salbutamol (total metered dose 2000 microg) or placebo at 2-min intervals on separate days. The effects on lung function (FEV(1) and PEF), heart rate, blood pressure, oxygen saturation, corrected QT interval (QTc), T-wave height and plasma potassium were assessed before each dose, 15 min after each dose, and at half-hourly intervals for 3 h following the final dose. RESULTS: Inhalation of formoterol or salbutamol resulted in significant improvement in lung function (measured 30 min after the last dose) when compared with placebo. There were no clinically important or statistically significant changes in heart rate, QTc, T-wave height, plasma potassium, oxygen saturation, or systolic and diastolic blood pressures with formoterol or salbutamol. One patient developed ventricular trigeminy after both formoterol and salbutamol. She had had ventricular ectopics on her screening electrocardiogram. CONCLUSION: Formoterol and salbutamol both produced significant improvement in lung function and were similarly well tolerated in high doses, as might be taken by a patient for relief of COPD symptoms.
Abstract: Exposure to allergens from house dust-mites (Der p 1) and domestic cats (Fel d 1) is associated with symptom severity in atopic subjects with asthma and rhinitis. Assessment of allergen exposure in the domestic environment is normally determined by measurement from a single floor site. We determined the variability of these allergens and protein throughout the whole living room floor area. Dust samples were collected from 1 m2 areas from 16 carpeted living room floors in Wellington, New Zealand, and analyzed for concentrations of Der p 1 and Fel d 1. Mean coefficients of variation for Der p 1 and Fel d 1 were 53.1% (range: 28.5-136.8) and 65.6% (range: 28.5-131.0), respectively. This study has demonstrated a large variation of house dust-mite and cat allergens within living room floors and thus assessment of a single sampling site may not be representative of an individual's exposure risk. House dust-mite and cat allergen levels from the center of the room, in front of a couch or chair, or from a corner of the room are similar to mean levels from the whole room. These sites may thus be representative of the whole living room floor in large-scale epidemiological studies.
Abstract: Endotoxin in house dust has been shown to be associated with asthma severity. Little is known about the influence of housing characteristics on endotoxin distribution. Using standardized methods, dust was sampled from a 1m(2) site and the whole accessible carpet area in selected Wellington, New Zealand homes (n = 77). Endotoxin was measured using a Limulus Amoebocyte Lysate assay. Relative humidity and temperature were recorded using sensors placed in carpet bases. Questionnaires were used to collect information on housing characteristics. All analyses were performed for endotoxin units (EU)/mg and EU/m2 for each site. Geometric mean endotoxin levels were 22.7 EU/mg [geometric standard deviation (GSD) = 2.4] or 30,544 EU/m2 (GSD = 3.2) from the 1m(2) site, and 28.4 EU/mg (GSD = 3.4) or 5653 EU/m2 (GSD = 6.4) from the whole room. After controlling for confounding, endotoxin was positively associated with dogs inside [geometric mean ratio (GMR): 0.9-2.0], total household occupants (GMR: 1.7-2.0, for 1 m2 sample only), vacuum cleaners <1-year old (GMR: 2.3-2.7), reusing vacuum dust collection bags (GMR: 1.4-3.1), steamcleaning or shampooing the carpet (GMR: 1.4-2.2) and high relative humidity (GMR: 1.4-1.6). Lower endotoxin was associated with floor insulation (GMR: 0.4-0.8), and north-facing living rooms (GMR: 0.4-0.8). This study has identified home characteristics that could be modified to reduce endotoxin exposure.
Abstract: BACKGROUND: Studies in Europe have reported a reduced prevalence of allergy in farmers' children. We aimed to determine if there is a similar reduction in allergy among New Zealand farm children. METHODS: Two hundred and ninety-three children participated (60%) aged 7-10 years, from selected schools in small towns and the surrounding rural area. Skin prick tests (SPT) to eight common allergens were performed. Parents completed questionnaires about allergic and infectious diseases, place of residence, exposure to animals, and diet, and they provided dust from the living-room floor. Endotoxin was measured using an Limulus amoebocyte lysate (LAL) assay and Der p 1 using enzyme-linked immunoassay (ELISA). RESULTS: Current farm abode was found to increase the risk of having symptoms associated with allergy, but not SPT positivity. Independent inverse associations were found for early-life exposures: at least weekly consumption of yoghurt with hayfever (odds ratio (OR) = 0.3, 95% confidence intervals (CI) 0.1-0.7) and allergic rhinitis (OR = 0.3, 95% CI 0.2-0.7); any unpasteurized milk consumption with atopic eczema/dermatitis syndrome (AEDS) (OR = 0.2, 95% CI 0.1-0.8); cats inside or outside with hayfever (OR = 0.4, 95% CI 0.1-1.0) and AEDS (OR = 0.4, 95% CI 0.2-0.8); dogs inside or outside with asthma (OR = 0.4, 95% CI 0.2-0.8); and pigs with SPT positivity (OR = 0.2, 95% CI 0.1-0.9). CONCLUSIONS: Despite finding a protective effect of early-life animal exposures, we found a greater prevalence of allergic disease on farms.
Abstract: AIM: To quantify the levels of Dermatophagoides pteronyssinus (Der p1) in different university student accommodation in Dunedin, and to assess relationships with housing characteristics and housekeeping practices. METHODS: Dwellings (n=178) were randomly selected from a database of first year university students in Dunedin. Dust samples were collected from both bed and the bedroom floor by standardised procedures. Der p1 levels were quantified by monoclonal antibody ELISA techniques. Details of housing characteristics, occupancy and housekeeping practices were obtained by questionnaire. RESULTS: Geometric mean (95% confidence intervals) Der p1 allergen levels from bedroom floors were: family homes (n=61) 5.58 (3.73-8.36) microg/g; student flats (n=43) 3.89 (2.49-6.07) microg/g; halls of residence (n=74) 0.26 (0.16-0.43) microg/g. Der p1 allergen levels from beds were: family homes 15.85 (9.78-26.57) microg/g; student flats 10.5 (6.41-17.19) microg/g; halls of residence 3.25 (2.33-4.54) microg/g. In all accommodation lower levels of Der p1 were found on the floor compared to the bed (p<0.005). Halls of residence had significantly lower Der p1 levels in both bed and floor (p<0.0005). Higher levels of Der p1 were associated with longer duration of occupancy, a history of condensation or mold in the accommodation, failure to use a hot wash for sheets, mattress age greater than one year and infrequent vacuuming of the bedroom floor. CONCLUSIONS: Wide variations in Der p1 levels were observed between different forms of student accommodation. Higher levels of Der p1 are found in family homes than in student flats or halls of residence.
Abstract: AIM: To compare advice provided by health food stores (HFS) and pharmacies in relation to medical conditions and assess the need for regulation of HFS. METHODS: We assessed the advice provided by 26 health food stores (HFS) and 26 pharmacies to an individual presenting with symptoms suggestive of moderate to severe asthma who had not seen a general practitioner. RESULTS: The advice provided by the two stores differed markedly. 22/26 pharmacy staff diagnosed asthma/probable asthma, whereas only 15/26 HFS staff reached the same conclusion. 92.3% of pharmacy staff compared to 34.6% of HFS staff referred the investigator to a doctor; 5 HFS advised the investigator against seeing a doctor. A wide variety of remedies were recommended by the HFS, none of which are known to be beneficial in the treatment of asthma. CONCLUSION: HFS promoting herbal products for medical conditions should be regulated in a similar fashion to shops that dispense pharmaceutical products.
Abstract: 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.
Abstract: BACKGROUND: A previous study of homes in Wellington, New Zealand showed that having carpets on floors was the most important determinant of floor Der p 1 levels, but there was much unexplained variability between houses in carpet levels. OBJECTIVE: To determine to what extent housing characteristics might explain this variability in Der p 1 levels between houses. METHODS: We returned to a selection of houses with carpets and sampled living room dust from 1 square metre for 1 min and from the whole floor at 5 m(2) per min. Der p 1 levels were estimated by double monoclonal antibody ELISA and are expressed as geometric mean microg/g and microg/m(2) (95% confidence intervals). Questionnaires were used to collect information on housing characteristics. RESULTS: Der p 1 levels were significantly higher in the 1 square metre sample (40.0, 31.9-50.2 microg/g; 53.4, 41.4-68.9 microg/m(2)) than in the whole room (25.8, 21.3-31.1 microg/g; 5.3, 3.8-7.4 microg/m(2)). However, results from the different sampling methods were correlated (r = 0.51, P = 0.001 for microg/g and r = 0.58, P = 0.001 for microg/m(2)). After controlling for possible confounders, houses with insulation or a room or garage below the living room had approximately half the Der p 1 concentration (P = 0.05 for both samples) and the amount of Der p 1 per m(2) (P = 0.004 for the 1 square meter sample, P = 0.06 for the whole room sample) than houses without these features. Having more than two children was associated with higher levels of Der p 1 in 1 square meter, significant (P = 0.05) for microg/m(2). Carpet underlay less than 8 mm thick was associated with an almost 3-fold increase in microg/m(2) Der p 1 (P = 0.03) and a 1.6-fold increase in microg/g Der p 1 (P = 0.08) in the whole room sample, when compared with thicker carpet underlays. CONCLUSION: The presence of insulation is the single most important housing characteristic explaining the between-house variability in Der p 1 levels on carpeted living room floors.
Abstract: AIMS: Previous studies have found high error rates in references in biomedical journals. The aim of this paper was to assess the accuracy of references in three Australian and New Zealand general medical journals. METHODS: References from the August 1999 issues of the Medical Journal of Australia, the New Zealand Medical Journal and the Australian and New Zealand Journal of Medicine were assessed for accuracy using PubMed of the National Library of Medicine. RESULTS: This study found a high rate of reference errors in Australian and New Zealand medical journals. The reference error rate ranged from 33.5 to 48.8%. The most frequent errors were in the author's names and in the title. CONCLUSIONS: The reference error rate in Australia and New Zealand medical journals is high and is preventable. Authors should be more diligent and preferably verify cited references against the original article.
Abstract: The objective of this study was to examine the relationship between the indoor environment, atopy and asthma in 7-9-year-old children. Cases and controls were randomly selected from children who participated in the International Study of Asthma and Allergies in Childhood (ISAAC) in Wellington, New Zealand. Cases were children with a previous diagnosis of asthma and current medication use (n = 233) and controls were children with no history of wheezing and no diagnosis of asthma (n = 241). Information was recorded about the indoor environment during the first year of life and currently. Dust was sampled from floors and beds and Der p 1 and Fel d 1 measured using enzyme-linked immunosorbent assays. Skin-prick tests were performed with eight common allergens. Sensitization to Dermatophagoides farinae (OR = 3.19; 95% CI 1.74-5.84), Dermatophagoides pteronyssinus (OR = 2.06; 95% CI 1.16-3.65) and cat (OR = 3.89; 95% CI 1.06-14.30) were independently associated with current asthma. The use of a sheepskin in the first year of life (OR = 1.91; 95% CI 1.11-3.33) was also independently associated with current asthma but current Der p 1 levels showed no association with current asthma. Exposures in early life may be more important than current exposures in determining asthma at age 7-9 years. Prospective studies are needed in New Zealand to determine the relative importance of early life exposures to Der p 1 and other risk factors for asthma.
Abstract: BACKGROUND: We have previously demonstrated that synthetic pillows contain significantly more Der p 1 than feather pillows. The aim of this study was to compare the accumulation of Der p 1 allergen on new synthetic and new feather pillows. METHODS: Der p 1 was measured in dust samples from pairs of synthetic and feather pillows placed together on 12 beds over a 12-month period. RESULTS: After 12 months synthetic pillows contained higher concentrations of Der p 1 (19.28 microg/g; 95% confidence interval: 9.76-38.07) than feather pillows (6.45 microg/g; 2.96-14.05). There was a significant correlation between Der p 1 concentrations of pillows at 12 months and Der p 1 concentrations of the mattresses at the beginning of the study (r = 0.72; P = 0.008 for both types of pillows). CONCLUSIONS: Synthetic pillows accumulate Der p 1 more rapidly than feather pillows and the accumulation rate of Der p 1 on pillows is governed by the Der p 1 concentration in the immediate environment they are placed in.
Abstract: We have examined the effect of reducing relative humidity (RH), with inbuilt mechanical ventilation and heat-exchange (MVHE) units, on house-dust-mite (HDM) counts and allergen levels, in a pilot study of 10 Wellington dwellings. Recent international prevalence studies in adults and children have confirmed a high prevalence of asthma in New Zealand. Sensitivity to HDM is common among the general population, and HDM is the major allergen associated with asthma. Recent studies of allergen levels have confirmed high concentrations of Der p 1 in the domestic environment. While humidity was significantly reduced in those dwellings fitted with ventilation units, no systematic effect on mites or Der p 1 was observed during the study period. When the reductions in humidity were examined in the context of the time spent below the critical equilibrium humidity (CEH), the intervention led to RH values below the CEH for only 39% of the total of 24-h periods for which measurements were made. Reducing RH by means of MVHE in New Zealand domestic dwellings does not lower humidity sufficiently, or long enough, to have any measurable effect on HDM populations.
Abstract: AIM: Sheepskins, which are often used as infant bedding in New Zealand, are known to harbour large quantities of house dust mites and their allergens. In this study we determined the rate of accumulation of the house dust mite allergen, Der p 1 on new sheepskins, and the effects of washing and dry cleaning on its removal. METHODS: New sheepskins were placed on living-room floors (n = 6) and mattresses (n = 6) in six domestic dwellings in Wellington. Sheepskin dust samples were collected by vacuuming before placement, and at two, four and six weeks, after which they were warm-washed. They were replaced for a further six weeks, then dry-cleaned. Dust samples were collected before and after washing and dry-cleaning, and from mattresses and living-room floors. Dust samples were analysed for Der p 1 by double monoclonal antibody ELISA. RESULTS: Der p 1 levels rapidly increased in sheepskins placed on living-room floors and mattresses to a geometric mean level (range) of 9.0 micrograms/g (1.1-102.2) and 29.4 micrograms/g (5.3-131.1) at six weeks, respectively. After warm-water washing and replacement for a further six weeks, these levels were higher at 75.5 micrograms/g (50.1-260.4) and 31.9 micrograms/g (11.1-75.2), respectively. Sheepskin Der p 1 accumulation correlated with mattress (r = 0.78), and living-room floor Der p 1 levels (r = 0.94). Warm water washing and dry-cleaning reduced sheepskins Der p 1 levels by a mean of 79.2% and 95.3%, respectively. CONCLUSIONS: Sheepskins rapidly accumulate house dust mite allergens from the domestic environment. Due to very high levels and rapid accumulation of Der p 1, sheepskins as infant bedding should be discouraged for infants at risk of sensitisation to house dust mites. If they are to be used then it is important that they are washed or dry-cleaned regularly.
Abstract: AIMS: Cat allergen (Fel d 1) is a known risk factor for asthma. Studies have demonstrated Fel d 1 in both public buildings and domestic dwellings where cats have never been. The aims of this study were to measure reservoir Fel d 1 levels in public buildings in New Zealand, to examine determinants of these levels and to compare them with previously measured domestic levels. METHODS: Dust was obtained in two centres (Wellington and Christchurch) from hotels, hospitals, rest homes, churches, primary schools, childcare centres, cinemas, bank head offices and aeroplanes; and from North Island ski lodges. Measurements of temperature and relative humidity were taken. Information was collected on building characteristics. Fel d 1 levels (microg/g of fine dust) for floors (n=203), beds (n=64) and seats (n=24) were expressed as geometric means (95% confidence intervals). RESULTS: Detectable Fel d 1 levels were found in 95% of floor samples, 91% of bed samples and 100% of seat samples. Fel d 1 levels [geometric mean (95% confidence intervals)] were significantly higher on cinema and domestic aircraft seats [36.8 (20.8-65.3) microg/g and 33.3 (28.0-39.7) microg/g respectively] than on floors [3.6 (2.5-5.1) microg/g and 2.4 (1.8-3.0) microg/g respectively]. Floor Fel d 1 levels in the public buildings sampled were lower than those of domestic dwellings without cats [0.9 (0.6-1.4) microg/g vs 1.7 (1.2-2.4)] microg/g in Wellington and [2.0 (1.6-2.6) microg/g vs 4.0 (2.7-6.0] microg/g in Christchurch. After controlling for potential confounders, floor Fel d 1 levels were higher with carpeted floors (p<0.001) and lower in banks and hospitals (p<0.001). CONCLUSION: Fel d 1 levels in public buildings are low in New Zealand public places except for cinema and domestic aircraft seats where all but one sample had Fel d 1 levels potentially high enough to precipitate asthma symptoms in sensitised individuals.
Abstract: BACKGROUND: High exposure to house dust mite and cat allergens in early life predisposes to allergic sensitization and to the development and persistence of asthma. Prevalence and severity of asthma are high in New Zealand. OBJECTIVE: The objective of this study was to determine the concentrations of Der p 1 and Fel d 1 in infant bedding in Wellington, New Zealand. METHODS: Infants were visited at home at a mean age of 11 weeks and again at 15 months. The concentration (microgram/g fine dust) and content (microgram/m2) of Der p 1 (154 infants) and Fel d 1 (75 infants) were measured in dust samples taken from each infant's bed. RESULTS: At 11 weeks, geometric mean (95% confidence intervals) Der p 1 levels were 18.3 micrograms/g (13.8 to 24.1) and 3.51 micrograms/m2 (2.4 to 5.2). By 15 months, Der p 1 had risen significantly to 44.0 micrograms/g (35.0 to 55. 3) and 49.0 micrograms/m2 (36.0 to 66.8). Bedding that included a sheepskin was used by a third of the infants and contained higher concentrations (microgram/g) and content (microgram/m2) of Der p 1 than beds without sheepskins. Cat ownership was the major determinant of Fel d 1 levels, with 48% of infants living with cats. At the first visit, the mean concentration of Fel d 1 in bedding was 44.6 micrograms/g (23.5 to 84.9) for houses with cats and 3.0 micrograms/g (2.1 to 4.3) for those without cats, remaining essentially unchanged at the second visit. When expressed as micrograms per square meter, there was a significant increase between visits, from 8.1 (3.9 to 16. 6) to 39.6 (19.9 to 78.5) in the cat-inclusive households. CONCLUSIONS: Extremely high levels of house dust mite allergen have been found in these infants' environments, which, together with the high levels of cat allergen in almost half who kept cats, are likely to be a major determinant of asthma prevalence and severity in New Zealand.
Abstract: AIM: To determine the effect of frequent vacuum cleaning of carpets on Der p 1, the major group one allergen of the house dust mite Dermatophagoides pteronyssinus. METHODS: Nine rooms and three hallways in the resident medical officers quarters at Wellington Hospital were regularly vacuum cleaned (daily, except weekends) over a five week period. Dust samples were collected before and at weekly intervals for Der p 1 measurement by a double monoclonal antibody ELISA technique. RESULTS: Der p 1 concentrations progressively declined from an initial geometric mean level (95% CI) of 4.47 micrograms/g fine dust (0.11-21.73) to 1.83 micrograms/g (0.29-9.57) after five weeks, a mean reduction of 48.0% (31.7-65.5). Similarly when expressed per unit area Der p 1 levels declined from 6.35 micrograms/m2 (1.15-35.16) to 1.66 micrograms/m2 (0.33-9.04), a mean reduction of 68.5% (58.6-78.3). CONCLUSIONS: Frequent vacuum cleaning over a short time significantly reduces house dust mite allergen levels in carpets. Larger long term trials are warranted to determine if greater reductions are possible that would be beneficial to house dust mite sensitive individuals.
Abstract: BACKGROUND: House dust mite allergens are a risk factor for asthma in New Zealand, and levels in domestic dwellings have been found to be high compared with levels in most other countries. Studies in other countries have demonstrated lower levels of Dermatophagoides pteronyssinus allergens in public places compared with levels in domestic dwellings. OBJECTIVES: The purpose of this study was to measure reservoir Der p 1 levels in public places in New Zealand and to examine determinants of these levels. METHODS: Reservoir dust was obtained in the two centers (Christchurch and Wellington) from hotels, hospitals, rest homes, churches, primary schools, childcare centers, cinemas, bank head offices, and airplanes; samples were also obtained from ski lodges. Single measurements of temperature and relative humidity were taken with thermohygrometers and an average humidity over 2 weeks was estimated with use of waxed wooden sticks. Information was collected on building construction, type of heating, and frequency of cleaning. Der p 1 levels (micrograms per gram of fine dust) for floor (n = 202), bed (n = 65), and seat (n = 24) samples in public places were expressed as geometric means (95% confidence intervals). RESULTS: Der p 1 levels in public places were significantly lower than domestic levels in both Wellington and Christchurch. Both floor and bed levels were higher in hotels than in other public places. After controlling for potential confounders, floor Der p 1 levels were higher with carpeted floors (p < 0.0001) and lower with recent cleaning (p = 0.02) and bed Der p 1 levels were higher with timber wall construction (p = 0.03). Other building, heating, or cleaning characteristics did not show significant association with allergen levels. CONCLUSION: Der p 1 levels were much lower in public places than in domestic dwellings with floor levels primarily affected by floor covering.
Abstract: OBJECTIVES: To measure levels of the major Dermatophagoidespteronyssinus allergen (Der p 1) in homes in Wellington, New Zealand, and to examine factors which affect these levels. METHODS: As part of a study of risk factors for asthma among 474 8-10-year-old children, standard procedures were used to collect reservoir dust and to measure Der p 1 levels on the living room floor and child's bedroom floor and bedding. Der p 1 levels were analysed both as geometric mean microg/g of fine dust and as microg/m2. Questionnaires collected information about factors which might influence these levels, and an average relative humidity in the bed and on the bedroom floor was also measured. RESULTS: Similar geometric mean levels of Der p 1 were found at each floor site - 25.5 microg/g (95% CI: 22.8-28.5) in the living room and 26.4 microg/g (95% CI: 23.7-29.3) on the child's bedroom floor. The geometric mean level of Der p 1 in the child's bed was 46.6 microg/g (95% CI: 42.3-51.3). After controlling for possible confounders, geometric mean living room and bedroom floor Der p 1 levels were significantly higher in households with older carpet than households with no carpets or newer carpets, and higher in the autumn. Households with three or more children had higher levels of Der p 1 than households with fewer children. Bedding levels were significantly higher in beds with kapok or inner sprung mattresses, or wool underlays and at relative humidities above the mean (51%). CONCLUSION: The very high levels of house dust mite allergen (Der p 1) found in Wellington are likely to be due to a variety of life-style and climatic factors. However, the type and age of floor covering appears to be the single most important factor.
Abstract: STUDY OBJECTIVE: To compare the maximal extrapulmonary effects of the beta-agonists albuterol and fenoterol in eight healthy volunteers. SUBJECTS AND METHODS: In this double-blind study, we have examined the maximum cardiac effects (electromechanical systole [QS2I]--a measure of inotropy, heart rate, BP) and metabolic effects (plasma K+ and cyclic adenosine monophosphate [cAMP]) of repeated inhalation of albuternol and fenoterol. In eight healthy volunteers, 400 microg of each drug was administered every 10 min until QS2I and plasma K+ had reached a plateau (+/- 0.1 mmo l/L for K+, and +/- 10 ms for QS2I). The maximum response (Emax) and the dose of albuterol required to produce 50% of the maximum response to fenoterol (ED50F) were calculated. RESULTS: The Emax for fenoterol was significantly greater than albuterol for plasma K+ (-1.4 vs -1.03 mmol/L; p<0.002), QS2I (-71.8 vs 57.5 ms; p=0.047), and cAMP (33.8 vs 18.1 nmol/L; p<0.002). The dose required to produce the ED50f was significantly greater for albuterol than for fenoterol with potency ratios of 1.75, 1.61, and 2.26 for plasma K+, QS2I, and cAMP, respectively. There were no significant differences between fenoterol and albuterol with respect to heart rate (Emax, 44.9 vs 32.5 beats/min; p=0.19; potency ratio, 1.98; p=0.052). CONCLUSIONS: These findings suggest that albuterol behaves as a partial agonist at beta-receptors when compared with fenoterol, and that when inhaled in doses currently recommended for severe asthma, albuterol will result in lesser maximum cardiac and metabolic effects than fenoterol. These findings are consistent with the hypothesis that the property of full receptor agonism may contribute to the increased risk of death associated with fenoterol.
Abstract: AIM. A number of studies have shown that increased salt intake is associated with worsening asthma. The aim of this study was to investigate the respiratory effects of digoxin (a potent inhibitor of Na+K+ATPase) in patients with asthma. METHODS. Eight asthmatic patients were given digoxin (0.5 mg/daily) or matching placebo for 8 days. Treatments were assigned using a randomised double blind, crossover design. Bronchial hyperresponsiveness to methacholine, forced expiratory volume is one second (FEV1, serum potassium (K), urinary sodium and K, heart rate, blood pressure and the QTc interval of the ECG were measured on each treatment. RESULTS. When compared to placebo, digoxin significantly decreased FEV1 (p<0.03); the QTc interval (p<0.05), and increased serum K (p<0.02). There was a tendency for digoxin to increase bronchial hyperresponsiveness. CONCLUSION. In this small study digoxin resulted in a decline in spirometry. Further studies in a larger group of patients should be performed to assess this potentially adverse effect of digoxin.
Abstract: We investigated whether the beta 2-agonists fenoterol and salbutamol decreased plasma selenium and glutathione peroxidase activity in patients with asthma as this may partially explain the findings of reduced selenium status in asthmatic patients. Nine patients with asthma were studied on 3 occasions and inhaled either fenoterol (5 mg), salbutamol (5 mg) or ipratropium bromide (0.5 mg) administered by nebulization using a randomized, double blind, crossover design. Plasma selenium, glutathione peroxidase activity and potassium were measured prior to drug administration and at 15, 30 and 60 minutes after drug. None of the drugs had any effect on plasma selenium or glutathione peroxidase activity. Ipratropium bromide did not affect plasma potassium. Both beta 2-agonists significantly decreased plasma potassium. The mean (SD) maximum decrease was -0.79 (0-18) mmol/l for fenoterol and -0.26 (0-03) mmol/l for salbutamol (both p < or = 0.01) confirming systemic absorption of the drugs. beta 2-agonists are unlikely to be responsible for the reduced selenium status found in some patients with asthma.
Abstract: 1. Haematologic parameters were measured in untreated borderline hypertensive (BHT) men, and weight and age matched with normotensive men to determine whether previously described increased haematocrit (Hct) in established hypertension is evident in borderline hypertension. 2. Haematocrit was significantly increased in BHT men (mean 0.46, s.d. 0.032) compared with normotensive men (mean 0.43, s.d. 0.014) and correlated significantly with mean arterial pressure in this group (r = 0.67, P = 0.036) independent of weight. 3. The correlation of blood pressure with Hct in BHT men supports the concept that increased Hct may contribute to increased blood viscosity and thus to raised arterial pressure.
Abstract: 1. Erythrocytic sodium-lithium (Na-Li) countertransport (CT) was measured in normotensive Maori and non-Maori by in vitro and in vivo methods to determine its relationship to erythrocytic hypernatraemia previously identified in Maori. 2. In vivo and in vitro CT rates were correlated within race and were similar between races. Countertransport rate was correlated with erythrocytic sodium concentration only in Maori. 3. The findings suggest the possibility of a genetically determined alteration in CT stoichiometry in Maori.
Abstract: A pilot study was conducted to identify nurses' attitudes and concerns pertaining to the care of people with human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS). Data were collected using an anonymous, voluntary questionnaire, which was made available to all nurses at a Wellington Area Health Board (New Zealand) hospital. Of 562 nursing staff, 286 (51%) responded, of which 74 (25.9%) had previously attended an HIV/AIDS workshop for Area Health Board staff. Of those staff handling blood, 132 (49.4%) always wore gloves, and only half of the respondents (n = 148, 51%) treated all body fluids as potentially HIV positive. The possible attrition rate from nursing positions in the canvassed hospital was 2.8%, with a further 43 (15.0%) undecided about resigning from their post. Only 36 nurses (12.5%) believed the employer did not provide adequate safety measures. The provision of education regarding HIV/AIDS, by the employer, was considered inadequate by 61 (21.3%) respondents. This study demonstrates that further safety and education needs should be attended to or reinforced.
Abstract: AIMS: to ascertain attitudes and concerns of laboratory staff towards handling of HIV positive biological samples. METHOD: an anonymous questionnaire regarding various aspects of biological sample handling was distributed to laboratory staff from the Wellington Area Health Board laboratories. RESULTS: of a total of 133 laboratory staff (response rate: 56.4%), five were seriously considering leaving, and another ten would have chosen another career if given prior information in regard to handling HIV positive biological samples. Of the responders, 22.8% and 38.3% considered that their employer does not provide adequate safety measures and education respectively in regard to HIV. CONCLUSIONS: handling of HIV positive biological samples does not greatly contribute to attrition amongst laboratory staff. Given the concern of laboratory staff for safety and education in regard to HIV, a continuous in-service educational programme would be desirable.
Abstract: Blood platelet counts and mean platelet volumes were determined at weekly intervals for eight weeks in 13 pre-menopausal and 11 post-menopausal females. Samples were analysed exactly two hours after blood collection on a Coulter S plus VTM particle counter. Pre-menopausal platelet counts were slightly higher than post-menopausal counts at each week, but the count was not affected by the menstrual cycle, intra-individual variation showing mean coefficients of variation (CV) of 7.4% and 5.2% respectively. The mean platelet volume was similar in pre- and post-menopausal groups at each week and showed little variability over time (mean CV 2.7% and 3.3%, respectively). Platelet parameters show little variability over time in either group and with no cyclical effects of menstruation apparent.
Abstract: In order to investigate the pharmacodynamic selectivity of a number of beta-receptor agonists currently used in asthma, we compared the pulmonary and extrapulmonary effects of repeated inhalations of epinephrine, fenoterol, isoproterenol, and metaproterenol in 12 patients with asthma in a randomized double-blind crossover study. The drugs were administered from metered-dose inhalers at 15-min intervals for five doses (total dose, 10 puffs of each compound). Measurements of heart rate, blood pressure, total electromechanical systole (as a measure of inotropic response), QTc interval, plasma potassium, and FEV1 were made 5 min after each dose and 30 min after the final dose. Fenoterol and metaproterenol had significantly greater inotropic, electrocardiographic, chronotropic, and hypokalemic effects than did both isoproterenol and epinephrine. There was no difference in the bronchodilating effect of metaproterenol, fenoterol, or isoproterenol although these agents caused a significantly greater increase in FEV1 than did epinephrine. The concept of increasing beta-2 selectivity for metaproterenol and fenoterol compared with isoproterenol are not supported in the clinical setting.
Abstract: In 83 healthy normotensive males aged 20-55 years the platelet count is positively correlated with the red cell count (r = 0.371; P = 0.0006), the white cell count (r = 0.358; P = 0.0009), and with weight (r = 0.252; P = 0.0269). The red cell count is also positively related with the white cell count (r = 0.242; P = 0.0278) and with weight (r = 0.326; P = 0.0039); while the white cell count is slightly correlated with weight (r = 0.210; P = 0.067). These findings provide further indirect evidential support for a haemopoetic growth factor acting on a single pluripotent stem cell.
Abstract: The reported inverse relationship between fractional urinary clearance of lithium (FCLi) and erythrocyte sodium-lithium countertransport (Na-Li CT) in normotensive and hypertensive subjects suggests that Na-Li CT may be a marker of proximal tubular sodium reabsorption. We have refuted this hypothesis in a multiracial study of 57 Caucasian and 48 Maori normotensive and hypertensive males aged 20-40 years. Na-Li CT was measured in vitro by standard Li efflux methodology, and in vivo by the Li cell:plasma (Li C:P) ratio 24 h after a 1 g oral dose of lithium carbonate. The Na-Li CT and Li C:P ratio were not significantly different in the two races and were strongly correlated within race, confirming the validity of the Li C:P ratio as an in vivo index of in vitro Na-Li CT. There was no correlation in either race between in vitro or in vivo erythrocyte membrane sodium transport indices and FCLi.
Abstract: The cardiovascular, respiratory, and hypokalemic effects of repeated inhalation of fenoterol, albuterol, and isoproterenol were compared in 12 subjects with stable asthma according to a double-blind, crossover design. Ipratropium bromide served as a control providing bronchodilatation without extrapulmonary effects. Subjects inhaled the beta-agonists on an equal-weight basis (400 micrograms) at 0, 30, 40, and 45 minutes. Measurements of heart rate, blood pressure, total electromechanical systole (measure of inotropic activity), preejection period, QTc interval, plasma potassium levels, and forced expiratory volume in 1 second were made 5 minutes after each dose and again at 60 and 75 minutes. There were no differences in the bronchodilating effect between the beta-agonists. However, both fenoterol and isoproterenol resulted in greater positive inotropic stimulation than did albuterol, and fenoterol caused a greater fall in plasma potassium levels than did the other beta-agonists.
Abstract: Differences in erythrocyte sodium-lithium countertransport rate and erythrocyte potassium concentration were found between 0900 h and 2100 h in ten healthy individuals. Sodium-lithium countertransport rates were lowest at 0900 h (x: 0.34 mmol/l per h; SD: 0.15) and highest at 1200 h (x: 0.42 mmol/l per h; SD: 0.16). Erythrocyte potassium concentrations increased progressively during the day, while erythrocyte sodium concentrations did not change significantly during the day. For comparative and epidemiological studies of erythrocyte sodium-lithium countertransport rate blood samples should be taken at the same time of the day.
Abstract: The kinetic parameters Vmax and Km of erythrocyte sodium-lithium countertransport (Na-Li CT), and the lithium cell to plasma ratio (Li C:P) measured 24 h after a 1-g oral dose of Li2CO3, were determined in 14 normotensive (NT) and 14 untreated mild hypertensive (HT) males matched for age and weight. Li C:P and Na-Li CT were strongly correlated (r = -0.73), p less than 0.001), confirming the validity of Li C:P as an in vivo index of Na-Li CT. No differences in Li C:P (NT: 0.27 +/- 0.07; HT: 0.23 +/- 0.06), Na-Li CT (NT: 0.39 +/- 0.10 mmol/L/h; HT: 0.43 +/- 0.10 mmol/L/h), Vmax (NT: 0.58 +/- 0.16 mmol/L/h; HT: 0.68 +/- 0.20 mmol/L/h), or Km (NT: 1.5 +/- 0.4 mmol/L; HT: 1.6 +/- 0.9 mmol/L) were found between NT and HT. Our data do not support the marker concept of erythrocyte Na-Li CT in human hypertension.
Abstract: Administration of the beta 2 adrenergic agonists fenoterol, salbutamol and terbutaline to volunteers significantly reduced plasma potassium concentration in a double-blind crossover study. There was no consistent effect of the three active compounds on erythrocyte sodium concentration. Storage of whole blood at 4 degrees C increased erythrocyte sodium concentration by 33% after 2 h; this could explain the differences between this and another study of the effects of beta 2 adrenergic agonists on erythrocyte sodium concentration. We conclude that the human erythrocyte is unsuitable as an indirect in vivo model to demonstrate stimulation of cellular sodium potassium transport mediated by beta 2 adrenergic agonists.
Abstract: Mean platelet volume, platelet count and platelet distribution width were determined in eight male subjects at monthly intervals over a 4-6 month period. Measurements were made on a Coulter S Plus VTM exactly 15 min and 2 h after blood collection. Long-term intra-individual variability for mean platelet volume showed a mean coefficient of variation (CV) of 1.60% at 15 min and 2.01% at 2 h after blood collection; for platelet count a mean CV of 3.18% at 15 min and 2.40% at 2 h; and for platelet distribution width a mean CV of 7.3% at 15 min and 6.5% at 2 h. Platelet parameters are stable over time in the normal male individual.
Abstract: The complexity of amiodarone disposition in blood and tissues gives rise to difficulty in determination of optimal therapeutic monitoring strategies. We have defined the within-patient variability of plasma and erythrocyte amiodarone and desethylamiodarone concentrations and electrocardiogram intervals [PR and corrected QT (QTc)] in 27 patients each sampled on three to four occasions during long-term stable amiodarone therapy. All individual repeated measurements were included in the concentration-effect analysis. The mean within-patient coefficients of variation for amiodarone and desethylamiodarone were significantly greater in erythrocytes, 46.0 and 24.5%, respectively, compared with plasma, 12.7 and 12.3%. Amiodarone and desethylamiodarone were significantly greater in erythrocytes, 46.0 and 24.5%, respectively, compared with plasma, 12.7 and 12.3%. Amiodarone and desethylamiodarone were strongly correlated (r = 0.29 p less than 0.004). There was a 10-fold variability in erythrocyte amiodarone for a given plasma level. These data emphasize the highly variable cellular distribution of amiodarone and desethylamiodarone in the same patient on stable dosage over time. Plasma amiodarone was significantly correlated with dosage (r = 0.98), and percent change in QTc, (r = 0.56, p less than 0.0001), but there was a fourfold variation in plasma amiodarone for a given QTc. Side-effect frequency was not related to plasma or erythrocyte amiodarone or desethylamiodarone concentrations. A clinically useful relationship between plasma concentration and effect could not be consistently demonstrated for amiodarone in the same individual during stable dosage.
Abstract: Healthy Maori males were found to have higher platelet counts (mean 295 x 10(9)/L: SD 46) compared to healthy nonMaori males (mean 253 x 10(9)/L; SD 50). Maori males had higher weights (mean 88.4 kg; SD 12.5) than nonMaori males (mean 81.0 kg; SD 9.0); and the platelet count was significantly correlated with weight (r = 0.30; p = 0.003). After weight adjustment significant differences between Maori and nonMaori males for platelet counts remained. These findings have implications for laboratory reference ranges, and may be of epidemiological significance in cardiovascular disease.
Abstract: The hypokalaemic effects of equal doses (5 mg) of fenoterol, salbutamol, terbutaline and an equal volume of saline administered by nebulization were compared in eight healthy subjects. Plasma potassium was measured at 15-min intervals for 60 min and at 90 min, 2, 4 and 6 h following administration. Fenoterol, salbutamol and terbutaline all significantly decreased plasma potassium when compared to saline; however, the magnitude and duration of this effect differed between the active agents. Both fenoterol and terbutaline significantly reduced plasma potassium for 4 h whereas salbutamol was only different from 30 to 120 min. The maximum decrease occurred with fenoterol (-0.78 mmol/l), followed by terbutaline (-0.70 mmol/l) and salbutamol (-0.33 mmol/l). Both terbutaline and fenoterol had a significantly greater effect compared with salbutamol. When administered by nebulization fenoterol and terbutaline are likely to have a greater hypokalaemic effect than salbutamol and this effect is likely to be more long lasting.
Abstract: Central sympathetic outflow and the baroreflex were measured as an integrated cardiopressor response to a noise stimulus during normal sleep, in 13 normotensives and 14 borderline hypertensives. The pressor response latency was prolonged in the borderline hypertensives, and the stimulus-induced increase in systolic and diastolic intra-arterial pressure was greater in the borderline hypertensives (23.0 +/- 7.3-16.2 +/- 5.6 mmHg) compared with the normotensives (16.7 +/- 5.9-13.6 +/- 4.6 mmHg; P less than 0.001), but the heart rate was not increased. Despite the increased pressor response, the baroreflex-mediated fall in the heart rate following the pressor response was reduced in the borderline hypertensives, indicating secondary adaptation to hypertension and a resetting, or downregulation, of central vasomotor control mechanisms in the borderline hypertensives relative to normotensives.
Abstract: A solution consisting of heparinized and buffered isosmolar magnesium chloride is described in which whole blood may be stored for preservation of erythrocyte sodium (Na) and membrane sodium-lithium countertransport (Na-Li CT). Correlation (r) of fresh versus 24-h stored erythrocytes for Na was 0.990 (y = 0.30 + 0.956x) and for Na-Li CT was 0.995 (y = -0.014 + 1.022x). Na-Li CT rate was preserved in the storage solution for up to five days and erythrocyte Na concentration for at least 24 h. The solution should find application in epidemiological studies of erythrocyte Na and Na-Li CT rate in human essential hypertension as the blood specimens require no centrifugation or erythrocyte washing procedures prior to laboratory analysis.
Abstract: We have investigated the change in amiodarone and desethylamiodarone concentrations in blood sampled from three different Vacutainer tubes: (a) sodium heparin, (b) gel separator (SST), and (c) no additive (plain tube). Amiodarone and desethylamiodarone concentrations were determined by a reverse-phase high pressure liquid chromatography technique in samples from 12 subjects on chronic amiodarone therapy. Amiodarone concentrations were significantly lower in plasma compared with serum from either gel separator (11.5%, p = 0.05) or no additive (13.5%, p = 0.01) tubes. Desethylamiodarone concentrations were significantly lower in plasma compared with serum from gel separator tubes (8.5%, p = 0.04) and were slightly lower compared with no additive tubes (4.4%, p = 0.41). Serum amiodarone and desethylamiodarone concentrations from either no additive or gel separator tubes yielded similar results. We conclude that significant amiodarone and desethylamiodarone concentration differences occur between serum and plasma, and that no binding of amiodarone and desethylamiodarone to the separator gel occurs.
Abstract: We have studied 27 patients on long-term treatment (6-60 months) with amiodarone (dose range 350 mg per week to 2800 mg per week) to ascertain whether the corrected QT interval could predict plasma amiodarone or plasma desethylamiodarone concentration. The patients were assessed on three or four occasions one month apart. There were positive correlations for delta % QTc and plasma amiodarone and delta % QTc and plasma desethylamiodarone. There was approximately a four-fold variation for delta % QTc and plasma amiodarone. This variation was not accounted for by between-occasion variation in the QTc interval, as the coefficient of variation was 2.1%. In six of the patients delta % QTc either decreased or did not change. delta % QTc is not a reliable predictor of plasma amiodarone concentration in the individual patient over time.
Abstract: A method is described for the in-vitro measurement of erythrocytic sodium-lithium countertransport rate (SLC) by direct assay of intra-erythrocytic lithium (Li) concentrations in Li loaded cells during controlled Li efflux. Bicarbonate stimulated erythrocytic Li loading to an approximate intracellular concentration of 3 mmol/l can be achieved within 4 min. Maximum SLC rates are achieved at intra-erythrocytic concentrations greater than 2.5 mmol/l. Lithium efflux is linear over 0-60 min, and independent of pH change. The within-batch coefficient of variation for positive displacement pipetting of Li loaded erythrocytes is 2.8%. Storage of erythrocytes in isosmotic MgCl2 for 24 h had no effect on the SLC. Intra-individual coefficient of variation for SLC was less than 6%. The reference range for Caucasian subjects (n = 43) was 0.14-0.49 mmol Li +/l erythrocytes/h.
Abstract: In a four week double-blind crossover study, flurbiprofen 200mg daily was compared with naproxen 750mg daily in the management of 30 patients with ankylosing spondylitis. Both treatments were found to be very effective in alleviating pain and stiffness. No significant difference in efficacy was discernible between the two drugs. Side-effects were more frequent with flurbiprofen. A small, but significant, increase in renal excretion of beta-n-acetyl glucosaminidase occurred during treatment with both naproxen and flurbiprofen. Although previous surveys have not shown evidence of renal damage, further surveillance of renal function in patients receiving long term treatment with these preparations to exclude possible renal impairment would be prudent.
