Domestication-related variation in social preferences in chickens is affected by genotype on a growth QTL.

A growth-related QTL on chicken chromosome 1 has previously been shown to influence domestication behaviour in chickens. In this study, we used Red Junglefowl (RJF) and White Leghorn (WL) as well as the intercross between them to investigate whether stress affects the way birds allocate their time between familiar and unfamiliar conspecifics in a social preference test ('social support seeking'), and how this is related to genotype at specific loci within the growth QTL. Red Junglefowl males spent more time with unfamiliar chickens before the stressful event compared to the other birds, whereas all birds except WL males tended to spend less time with unfamiliar ones after stress. A significant QTL locus was found to influence both social preference under undisturbed circumstances and social support seeking. The WL allele at this QTL was associated not only with a preference for unfamiliar individuals but also with a shift towards familiar ones in response to stress (social support seeking). A second, suggestive QTL also affected social support seeking, but in the opposite direction; the WL allele was associated with increased time spent with unfamiliar individuals. The region contains several possible candidate genes, and gene expression analysis of a number of them showed differential expression between RJF and WL of AVPR2 (receptor for vasotocin), and possibly AVPR1a (another vasotocin receptor) and NRCAM (involved in neural development) in the lower frontal lobes of the brains of RJF and WL animals. These three genes continue to be interesting candidates for the observed behavioural effects.

Domestication-related genetic effects on social behavior in chickens - effects of genotype at a major growth quantitative trait locus.

Domestication is an evolutionary process in which animals become adapted to a life in close proximity to humans. There are typically specific selection pressures associated with this, including living in larger social groups than their wild ancestors. We hypothesized that the genotype at a major growth QTL could affect aspects of social behavior in chickens as well. We performed social behavior tests in red junglefowl (RJF) and White Leghorn (WL) chickens and in chickens from a selected advanced intercross line (SAIL) between RJF and WL, selected for different genotypes at a microsatellite marker locus within the QTL region. Four-week-old pure WL inspected strangers significantly more than pure RJF. Male 4-wk-old SAIL birds, homozygous for the WL allele at the marker locus, differed from those with RJF alleles in a similar way as the pure WL differed from RJF. Furthermore, 155- to 170-d-old male SAIL birds homozygous for the WL allele at the marker locus were less aggressive to unfamiliar conspecifics in a dominance test. The results suggest that domestication has caused changes in social behavior, which, in males, may partly depend on variations in the genotype at the growth QTL where the avian homolog of the arginine vasopressin receptor 1a (AVPR1a) is located. This gene is therefore one of several putative candidate genes for future research.

A retrospective database study comparing treatment outcomes and cost associated with choice of fixed-dose inhaled corticosteroid/long-acting beta-agonists for asthma maintenance treatment in Germany.

AIMS: This retrospective, observational cohort study aimed to compare treatment outcomes and healthcare costs in the year after initiation of maintenance treatment with budesonide/formoterol or salmeterol/fluticasone in a German healthcare setting. METHODS: Data on German asthma patients initiating treatment with budesonide/formoterol or salmeterol/fluticasone between June 2001 and June 2005 were obtained from the IMS Disease Analyzer database. The primary outcome was the probability of treatment success, defined according to short-acting beta(2)-agonist prescriptions and switches or addition of controller medications, during the postindex year. A secondary definition of treatment success included hospitalisations and oral corticosteroid (OCS) prescriptions. Secondary outcomes included severe asthma exacerbations, defined as >or=1 OCS prescription, asthma-related hospitalisation and/or referral. The effect of treatment on costs was estimated using generalised linear models, adjusting for patient and physician characteristics. RESULTS: There were no significant differences between the budesonide/formoterol (n = 1456) and salmeterol/fluticasone (n = 982) groups in disease severity markers in the pre-index year. Patients on budesonide/formoterol had a 44% greater probability of treatment success [odds ratio (OR): 1.44; p = 0.0003] according to the primary definition and a 26% greater probability (OR: 1.26; p = 0.0119) according to the secondary definition, fewer severe exacerbations (-33.4%; p = 0.0123) and fewer OCS prescriptions (-31.5%; p = 0.0082) compared with salmeterol/fluticasone, after controlling for baseline characteristics. Adjusting for covariates, budesonide/formoterol had a significant inverse relationship on asthma-related costs compared with salmeterol/fluticasone (-13.4%; p < 0.001). Total cost (asthma- and non-asthma-related costs) was 12.6% lower for budesonide/formoterol (p < 0.0001). CONCLUSION: This study suggests that for patients with chronic asthma in Germany, budesonide/formoterol rather than salmeterol/fluticasone had a higher likelihood of treatment success, and that budesonide/formoterol is the less costly option. Although the cohorts appeared to be well matched at baseline, the results should be interpreted with caution given the observational nature of the study.

Cost-effectiveness of budesonide/formoterol for maintenance and reliever asthma therapy.

BACKGROUND: Budesonide/formoterol (Symbicort) Maintenance and Reliever Therapy (SMART) is an effective asthma-management approach that treats symptoms with rapid increases in budesonide/formoterol. The cost-effectiveness of SMART vs higher fixed-dose budesonide/formoterol or salmeterol/fluticasone is unknown. METHODS: This 6-month, double-blind study randomized patients with asthma uncontrolled by inhaled corticosteroids alone (n = 3335; age > or =12 years) to budesonide/formoterol 160/4.5 microg b.i.d. plus additional doses as needed (SMART), budesonide/formoterol 320/9 microg b.i.d. plus as-needed terbutaline, or salmeterol/fluticasone 50/250 microg b.i.d. plus as-needed terbutaline. Economic analysis, assuming health care and societal perspectives, applied 2004 UK and Australian unit costs to pooled resource-use data. The effectiveness variable was the rate of severe exacerbations/patient/6 months. RESULTS: Patients treated using the SMART approach experienced fewer severe exacerbations than fixed-dose budesonide/formoterol and salmeterol/fluticasone patients (0.12 vs 0.16 and 0.19 events/patient/6 months, respectively; P < or = 0.0048). Budesonide/formoterol (Symbicort) Maintenance and Reliever Therapy provided similar improvements in other markers of asthma control at a lower overall daily inhaled corticosteroid dose compared with fixed-dose treatment. Study drug costs accounted for a majority of both direct costs (DC; 78-87%) and total costs (TC; 50-63%) for all treatments, and were significantly lower in the SMART group compared with the fixed-dose groups (P < or = 0.0014). Direct and TC per patient/6 months were lower for SMART vs salmeterol/fluticasone (DC:-AUS$154, P < 0.0001; TC:-AUS$163, P = 0.0036;-87 pound sterling, P = 0.0026) and vs budesonide/formoterol using UK costs (DC:-73 pounds sterling, P < 0.0001; TC:- 91 pounds sterling, P = 0.0014). Costs tended to be lower for SMART vs budesonide/formoterol using Australian costs (DC:-AUS$35, P = 0.16; TC:-AUS$70, P = 0.20). Results were stable under sensitivity testing. Indirect resource use and cost were not significantly different between groups. CONCLUSION: Compared with higher fixed-dose budesonide/formoterol and salmeterol/fluticasone, SMART reduces the incidence of severe exacerbations at a lower or similar overall cost and can be considered a cost-effective treatment regimen.

Localization of allergens in the domestic mite Lepidoglyphus destructor.

The non-pyroglyphid domestic mite Lepidoglyphus destructor is a major source of allergen causing respiratory symptoms in farming environments. This study is the first to focus on the localization of the allergens in the non-pyroglyphid domestic mite Lepidoglyphus destructor. Cryostat-cut sections of L. destructor mite bodies and faecal pellets were probed with one of three mouse monoclonal antibodies (MoAbs) raised against L. destructor or with patient sera, and stained with immunoperoxidase. Eight sera were RAST-positive to L. destructor and L. destructor faecal pellets. These eight RAST-positive patient sera labelled the wall of the L. destructor gut and two of them also the faecal pellets. The MoAbs additionally labelled parts of the exoskeleton and reacted with a majority of the faecal pellets. Cryostat-cut sections of Dermatophagoides pteronyssinus mite bodies and faecal pellets were probed with L. destructor MoAbs, which resulted in only slight staining of a few faecal pellets. The results suggest that at least one L. destructor allergen is associated with digestion.

Storage mites dominate the fauna in Swedish barn dust.

The mite fauna in hay dust of 16 farms located on the island of Gotland was analysed to establish whether there is a clear relationship between environmental exposure to storage mites and development of allergic symptoms. Eight of these farms belonged to farmers with respiratory symptoms related to barn dust (RS) and eight to healthy farmers (H). All farmers had previously participated in an epidemiological survey of hypersensitivity to respiratory allergens. The symptomatic farmers had not only a positive RAST to storage mites but they developed more than a 20% fall in FEV1 when challenged with Lepidoglyphus destructor (L. destructor) extract. The asymptomatic farmers were all negative in RAST to storage mites. Mites were found on all farms and the degree of infestation varied enormously, mite counts ranging from 75-150,000 mites/g dust. Five genera were detected but the different mite species were not represented on all farms. L. destructor was the dominating species on 13 of 16 farms. Samples from RS farms contained a significantly higher number of mites than H farms. The results of this study are in good agreement with our earlier studies showing that L. destructor is the most important allergen causing symptoms from both upper and lower airways among farmers.

Lack of allergenic cross-reactivity between storage mites and Dermatophagoides pteronyssinus.

The allergenic cross-reactivity between storage mites (Lepidoglyphus destructor, Glycyphagus domesticus, Tyrophagus putrescentiae and Acarus siro) and the house dust mite Dermatophagoides pteronyssinus was studied with the radio-allergo-sorbent test (RAST) and the RAST inhibition technique. RAST-positive sera were obtained from fifty-three farmers who were positive to at least one of the four storage mites. Sera from twelve of these farmers, eight of whom were also positive to D. pteronyssinus, were investigated with the RAST inhibition technique. No significant correlations were found between IgE-antibody levels to any single storage mite and D. pteronyssinus. There was no correlation between the RAST results to A. siro and G. domesticus, whereas a significant correlation was found between L. destructor, G. domesticus and T. putrescentiae. The RAST inhibition studies confirmed the greater allergenic similarity between L. destructor, G. domesticus and T. putrescentiae than between A. siro and the other three storage mites. The results of our studies support the hypothesis that each of the storage mites and D. pteronyssinus possess their own unique allergen or allergens. Furthermore, L. destructor, G. domesticus and T. putrescentiae seem to be allergenically more closely related to each other than to A. siro.

Storage mite allergy is common in a farming population.

The prevalence of storage mite allergy was investigated in an epidemiological study of respiratory symptoms in farmers on Gotland, an island in the Baltic Sea. A questionnaire concerning work-related and chronic symptoms from the airways and eyes was completed by 2578 farmers. A sample of 440 farmers subsequently underwent examination comprising skin-prick tests (animal danders, pollens, moulds and house dust mite), blood sampling for RAST against four storage mites (Acarus siro, Lepidoglyphus destructor, Tyrophagus putrescentiae and Glycyphagus domesticus) and total IgE analyses. Immediate onset hypersensitivity reactions in the airways and eyes were very common among active farmers on Gotland, the prevalence being as high as 40.0%. The prevalence of atopic allergy was 15.6%. Allergy to storage mites was diagnosed, from the case history and a positive RAST to at least one of the four storage mites, in fifty-two of 440 studied farmers (12%), corresponding to a calculated prevalence of storage mite allergy in the whole farming population of Gotland of 6.2%. The corresponding prevalence among farmers with hypersensitivity symptoms was 15.4% and among those with possibly IgE-mediated symptoms it was as high as 37.8%. The present study clearly demonstrates a high prevalence of allergy to storage mites among farmers with respiratory symptoms.

Differences in chemical composition of plants grown at constant relative growth rates with stable mineral nutrition.

Leaf chemistry of a willow clone (Salix aquatica Smith) differed significantly when grown at constant relative growth rates depending upon the relative availability of nutrients and light. Concentration of amino acids and nitrate were high in plants grown with a relative surplus of nutrients. Concentrations of starch, tannin, and lignin, on the other hand, were high in plants grown with a relative surplus of carbon. Photosynthetic rates, expressed per unit leaf area, were similar when plants were grown under high light conditions, regardless of nutrient availability. Dark respiration was much higher in plants supplied with abundant nutrients than in those with a more limited supply, reflecting differences in nitrogen concentration of the tissue. The experimental approach allows plants to be grown to a standard size with differing, but highly uniform chemistry. Plants grown in such a manner may provide good experimental material to evaluate interactions between herbivores or pathogens and their hosts.

Mites living in hay: an important allergen source?

Fifty-two farmers and 21 non-farmers with symptoms related to hay contact were investigated. Skin prick tests (SPT) and RAST were performed with an extract made of barn dust (BDE) consisting of hay remnants. At microscopy, the barn dust was found to contain large amounts of dead mites, most of them identified as Lepidoglyphus destructor and Acarus siro. Twenty-one patients (9 farmers and 12 non-farmers) had positive RAST or BDE, with a good correlation to the case histories. Other allergies, especially to Dermatophagoides pteronyssinus, pollens, and animal danders were also common among patients. However, there was no correlation between positive SPT and RAST to BDE and any other allergen tested. This indicates that BDE contains distinct allergens, most likely of mite origin.