Sex differences in 3- to 5-year-old children's motor competence: A pooled cross-sectional analysis of 6241 children.

There is some, albeit inconsistent, evidence supporting sex differences in preschoolers' motor competence (MC), with these observations not uniform when analyzed by age, and cultural groups. Thus, this study examined sex differences across ages in 3- to 5-year-old children's MC. A cross-country pooled sample of 6241 children aged 3-5 years (49.6% girls) was assessed for MC using the Test of Gross Motor Development-2nd/3rd edition, and children were categorized into groups of age in months. Multiple linear regression models and predictive margins were calculated to explore how sex and age in months affect scores of MC (i.e., locomotor and ball skills), with adjustments for country and BMI. The Chow's Test was used to test for the presence of a structural break in the data. Significant differences in favor of girls were seen at 57-59 and 66-68 months of age for locomotor skills; boys performed better in ball skills in all age periods, except for 42-44 and 45-47 months of age. The higher marginal effects were observed for the period between 45-47 and 48-50 months for locomotor skills (F = 30.21; and F = 25.90 for girls and boys, respectively), and ball skills (F = 19.01; and F = 42.11 for girls and boys, respectively). A significantly positive break point was seen at 45-47 months, highlighting the age interval where children's MC drastically improved. The identification of this breakpoint provides an evidence-based metric for when we might expect MC to rapidly increase, and an indicator of early delay when change does not occur at that age.

An ELISA for recombinant Lepidoglyphus destructor, Lep d 2, and the monitoring of exposure to dust mite allergens in farming households.

BACKGROUND: Exposure to indoor allergens, such as dust mites, has been recognized as a risk factor for sensitization and symptoms. OBJECTIVE: To develop a two-site ELISA for the determination of Lep d 2 in the reservoir, to measure dust mite allergen exposure (Lep d 2, Der p 1, Der f 1 and Der 2) in farm households, and to investigate whether exposure to these allergens is associated with sensitization, asthma and rhinoconjunctivitis. METHODS: Monoclonal antibodies to recombinant (r)Lep d 2 were produced with standard hybridoma technique. Dust samples from 393 households were analysed for allergen content by two-site ELISA methods. RESULTS: A two-site Lep d 2 ELISA was developed with a detection limit of 0.09 microg/g. The assay was highly reproducible and levels of Lep d 2 showed a strong correlation with the number of Lepidoglyphus mites (r(s): 0.7; P = 0.0002). Lep d 2 was detected in 20% of the homes; levels ranged from 0.09 to 1.7 microg/g of dust. Der p 1 was recorded in 59% of the samples, ranging from 0.055 to 139 microg/g, and Der f 1 and Der 2 in 40% and 50% of the samples, ranging from 0.055 to 24.5 microg/g and 24.3 microg/g, respectively. Dermatophagoides allergens were significantly higher in mattresses than in carpets (P < 0.0001), but this difference was not observed with Lep d 2. A strong relationship between immunoglobulin (Ig)E to rLep d 2 and asthma (OR = 10.4) and rhinoconjunctivitis (OR = 7.5) was seen. Furthermore, sensitization to D. pteronyssinus was significantly associated with asthma (OR: 13.7) and rhinoconjunctivitis (OR: 5.7). CONCLUSION: When assessing mite allergen exposure in rural homes, not only the Der p 1, Der f 1 and Der 2 allergens, but also the Lep d 2 allergen should be taken into consideration.

A new method for collecting airborne allergens.

BACKGROUND: Measurement of airborne allergens has hitherto been done with the use of fixed-location pumps or personal air samplers. Our objective was to find out whether ionizers could be good tools for collecting airborne allergens. As a model we have used cat allergen (Fel d l). We have compared Fel d l levels collected by the ionizer at different time periods, as well as comparing Fel d l levels obtained with the ionizer with those of low- and high-volume pumps. METHODS: Dust samples from floors and air samples collected with ionizers and pumps, obtained in 31 homes with cat, 23 homes without cats, and 28 day-care centres, were analysed for cat allergen content (Fel d I) by ELISA. RESULTS: Fel d l was present in the reservoir in all homes with cats, ranging from 660 to 375,000 ng/g (GM 75,000) and in the air collected by the ionizer from 2.0 to 204 ng/24 h (GM 19.3). The allergen in homes without cat varied from < 55 to 1,800 ng/g (GM 166). Corresponding levels in air were found in two of these homes (2.3 and 7.3 ng/24 h). There was a correlation between the number of cats and the amount of airborne cat allergen (r: 0.47; P < 0.05). The levels in day-care centres were < 55 to 3,070 ng/g in dust (GM 360) and < 1.1 to 7.9 ng/24 h in the air (GM 1.6). We obtained a moderately strong correlation between air and dust samples in homes with cats (rs: 0.64; P< 0.001) and in day-care centres (rs: 0.49; P<0.05). We found that a collection period of 24 h is preferable for the ionizer. The intrahome reliability coefficient was nearly two times higher for the ionizer (r: 0.69) than the pump (r: 0.39). CONCLUSIONS: The ionizer seems to be a good tool for monitoring the environment. It is easy to use and silent and does not disturb the airflow in the room.

Exposure to an abundance of cat (Fel d 1) and dog (Can f 1) allergens in Swedish farming households.

BACKGROUND: Earlier studies have shown that farmers are to a low degree sensitized to animal allergens. We have measured the amount of cat (Fel d 1) and dog (Can f 1) in farm households and examined the relationship between exposure and sensitization to cat and dog allergens. METHODS: Dust samples from the homes of 403 farmers who had participated in an epidemiologic follow-up study on respiratory symptoms were analyzed for allergen content by two-site ELISA methods. RESULTS: Fel d 1 was detected in 99.5% of the farmers' households ranging from 0.055 to 1455 microg/g dust in mattresses (GM 13.2) and to 3775 microg/g dust in living-room carpets (GM 17.1). Can f 1 was detected in 90.6% of the households from 0.2 to 116 microg/g dust in mattresses (GM 2.0) and to 504 microg/g dust in carpets (GM 4.3). Homes with pets present had the highest levels of the allergens (P<0.001). A total of 8.4% and 7.4% of the farmers were sensitized to cat and dog, respectively. A significant correlation was noted between exposure to the allergens and specific IgE to cat and dog, respectively (P<0.001). Sensitization to cat (OR = 4.9) and dog (OR = 17.8) was significantly associated with asthma. CONCLUSIONS: In spite of the abundance of Fel d 1 and Can f 1, farmers are only to a low degree sensitized to cats and dogs.