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Biomedical subjects

P Fitzharris

Publications and source records attributed to P Fitzharris.

At least 19 recordsLinked to original sources
PubMed2006

Is the effect of probiotics on atopic dermatitis confined to food sensitized children?

BACKGROUND: Probiotics have previously been shown to reduce the severity of atopic dermatitis (AD) in infants and children. OBJECTIVE: To examine the effect of two probiotics (Lactobacillus rhamnosus and Bifidobacteria lactis) on established AD in children. SUBJECTS AND METHODS: Atopic children with current dermatitis received 2 x 10(10) colony forming units/g of probiotic (n=29) or placebo (n=30). Both were given daily as a powder mixed with food or water. SCORing Atopic Dermatitis (SCORAD; developed by the European Task Force on Atopic Dermatitis) a measure of the extent and severity of AD, was assessed at baseline, 2 and 12 weeks after starting treatment and 4 weeks after treatment was discontinued. RESULTS: SCORAD geometric mean score at baseline was 26.0 (21.9-30.8) in the probiotic group and 35.1 (28.9-42.8) in the placebo group (P=0.02). After adjustment for these between-group baseline differences there was no significant improvement in AD at 12 weeks, SCORAD geometric mean ratio: 0.80 (95% confidence level (CI) 0.62-1.04, P=0.10). Among the food sensitized children, there was an improvement in those treated with probiotics, SCORAD geometric mean ratio: 0.73 (95% CI 0.54-1.00, P=0.047). CONCLUSION: In this study a combination of Lactobacillus rhamnosus and Bifidobacteria lactis improved AD only in food sensitized children.

Bifidobacterium↗
PubMed2003

House dust-mite allergen and cat allergen variability within carpeted living room floors in domestic dwellings.

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), respectively. This study has demonstrated a large variation of house dust-mite and cat allergens within living room floors and thus a single sampling site may not be representative for assessment 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.

Air Pollution, Indoor↗
PubMed2003

Determinants of endotoxin levels in carpets in New Zealand homes.

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.

Adult↗
PubMed2003

House dust-mite allergen and cat allergen variability within carpeted living room floors in domestic dwellings.

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.

Air Pollution, Indoor↗
PubMed2002

Farm residence and exposures and the risk of allergic diseases in New Zealand children.

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.

Agriculture↗
PubMed2001

The importance of housing characteristics in determining Der p 1 levels in carpets in New Zealand homes.

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.

Air Pollution, Indoor↗
PubMed1999

Indoor environment, atopy and the risk of the asthma in children in New Zealand.

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.

Air Pollution, Indoor↗
PubMed1999

House dust mite allergen (Der p 1) accumulation on new synthetic and feather pillows.

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.

Allergens↗
PubMed1999

Expression and translocation of Rac2 in eosinophils during superoxide generation.

Eosinophils induce tissue injury by releasing granule-associated cytotoxic proteins, lipid mediators and superoxide anions in response to appropriate stimuli. Superoxide generation associated with respiratory burst is largely dependent on the assembly of the NADPH oxidase complex in the membrane, consisting of membrane-bound cytochrome b558 and translocated p47phox and p67phox. The activation of this complex is critically dependent on the translocation of GTP-bound Rac1, or its homologue Rac2, from the cytosol to the membrane in neutrophils. Rac expression has not yet been fully characterized in eosinophils. We proposed that eosinophils translate and express Rac2 and its GDP-dissociation inhibitor, RhoGDI. Furthermore, we hypothesized that Rac2 translocates along with p47phox and p67phox proteins from the cytosol to the plasma membrane during respiratory burst. By reverse transcription-polymerase chain reaction analysis and sequencing of the amplified product, guinea-pig eosinophils were found to express Rac2 mRNA, exhibiting 93% homology with the human Rac2 sequence. Rac1 mRNA was also detected in eosinophils but not its translated product. In contrast, Rac2 protein expression was detected using a specific antibody. In subcellular fractions, Rac2 was found to translocate, along with p47phox and p67phox, from cytosol to plasma membrane-associated fractions following phorbol myristate acetate stimulation, while RhoGDI remained within cytosolic fractions. These findings suggest that Rac2 is preferentially expressed and activated in eosinophils, and is likely to be a crucial regulator of the release of reactive oxygen species from these cells during inflammatory reactions.

Amino Acid Sequence↗