| 1. |
- Amin, H., et al.
(författare)
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Indoor Airborne Microbiome and Endotoxin: Meteorological Events and Occupant Characteristics Are Important Determinants
- 2023
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 57:32, s. 11750-11766
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Tidskriftsartikel (refereegranskat)abstract
- Minimal research exists onthe factors influencing the indoorbacterial community. Despite their proposed importance for health,here we report environmental factors influencing the composition ofthe indoor bacterial communities. Airborne bacteria and endotoxin may affect asthma andallergies.However, there is limited understanding of the environmental determinantsthat influence them. This study investigated the airborne microbiomesin the homes of 1038 participants from five cities in Northern Europe:Aarhus, Bergen, Reykjavik, Tartu, and Uppsala. Airborne dust particleswere sampled with electrostatic dust fall collectors (EDCs) from theparticipants' bedrooms. The dust washed from the EDCs'clothes was used to extract DNA and endotoxin. The DNA extracts wereused for quantitative polymerase chain (qPCR) measurement and 16SrRNA gene sequencing, while endotoxin was measured using the kineticchromogenic limulus amoebocyte lysate (LAL) assay. The results showedthat households in Tartu and Aarhus had a higher bacterial load anddiversity than those in Bergen and Reykjavik, possibly due to elevatedconcentrations of outdoor bacterial taxa associated with low precipitationand high wind speeds. Bergen-Tartu had the highest difference (ANOSIM R = 0.203) in & beta; diversity. Multivariate regressionmodels showed that & alpha; diversity indices and bacterial and endotoxinloads were positively associated with the occupants' age, numberof occupants, cleaning frequency, presence of dogs, and age of thehouse. Further studies are needed to understand how meteorologicalfactors influence the indoor bacterial community in light of climatechange.
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| 2. |
- Jacinto, Tiago, et al.
(författare)
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Evolution of exhaled nitric oxide levels throughout development and aging of healthy humans
- 2015
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Ingår i: Journal of Breath Research. - : IOP Publishing. - 1752-7155 .- 1752-7163. ; 9:3
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Tidskriftsartikel (refereegranskat)abstract
- It is not fully understood how the fraction of exhaled nitric oxide (FeNO) varies with age and gender in healthy individuals. We aim to describe the evolution of FeNO with age, giving special regard to the effect of gender, and to relate this evolution to natural changes in the respiratory tract. We studied 3081 subjects from NHANES 2007-08 and 2009-10, aged 6-80 years, with no self-reported diagnosis of asthma, chronic bronchitis or emphysema, and with normal values of blood eosinophils and C-reactive protein. The relationship of the mean values of FeNO to age, in all participants and divided by gender, was computed, and compared with changes in anatomic dead space volume and forced vital capacity. A change-point analysis technique and subsequent piecewise regression was used to detect breakpoints in the evolution of FeNO with age. Three distinct phases in the evolution of FeNO throughout the age range 6-80 years can be seen. FeNO values increase linearly between 6-14 years of age in girls and between 6-16 years of age in boys, in parallel with somatic growth. After that, FeNO levels plateau in both genders until age 45 years in females and age 59 years in males, when they start to increase linearly again. This increase continues until age 80. Our data clearly show a triphasic evolution of FeNO throughout the human age range in healthy individuals. This should be accounted for in development of reference equations for normal FeNO values.
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| 3. |
- Malinovschi, Andrei, et al.
(författare)
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FeNO as a predictor of asthma control improvement after starting inhaled steroid treatment
- 2014
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Ingår i: Nitric oxide. - : Elsevier BV. - 1089-8603 .- 1089-8611. ; 40, s. 110-116
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: The fraction of NO in exhaled air (FeNO) is a marker of inflammation in asthma. The aim of the present study was to assess, in a real-world setting, whether only high ( >= 50 ppb) FeNO levels predict improvement in asthma control when being treated with inhaled corticosteroids (ICS), as suggested by current guidelines on the clinical use of FeNO. Methods: FeNO and asthma control were assessed in a retrospective observational study in 153 non-smoking, steroid-nave, adult subjects with asthma with a mean age of 40 years both before and after 6 weeks (median follow-up time) of treatment with 500 mu g beclomethasone (median). Results: Having at the initial visit intermediate FeNO ( >= 25 and <50 ppb) and high FeNO ( >= 50 ppb), compared to normal FeNO (<25 ppb), were associated with a larger proportion of subjects achieving an improvement of Asthma Control Questionnaire (ACQ) score with >= 1 (78% and 67% vs 43%, p <0.05) or both >= 1 improvement and asthma control at follow-up (31% and 37% vs 4%, p < 0.05). These associations were consistent in multiple logistic regression models after adjustments for confounders. Conclusions: It is not only high but also intermediate FeNO levels that are associated with a significant improvement in asthma control after starting ICS treatment. This challenges current clinical guidelines stating that only high FeNO levels predict response to ICS treatment.
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| 4. |
- Mendez-Enriquez, Erika, et al.
(författare)
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IgE cross-linking induces activation of human and mouse mast cell progenitors
- 2022
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Ingår i: Journal of Allergy and Clinical Immunology. - : Elsevier. - 0091-6749 .- 1097-6825. ; 149:4, s. 1458-1463
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Tidskriftsartikel (refereegranskat)abstract
- Background: The concept of innate and adaptive effector cells that are repleted by maturing inert progenitor cell populations is changing. Mast cells develop from rare mast cell progenitors populating peripheral tissues at homeostatic conditions, or as a result of induced recruitment during inflammatory conditions.Objective: Because FceRI-expressing mast cell progenitors are the dominating mast cell type during acute allergic lung inflammation in vivo, we hypothesized that they are activated by IgE cross-linking.Methods: Mouse peritoneal and human peripheral blood cells were sensitized and stimulated with antigen, or stimulated with anti-IgE, and the mast cell progenitor population analyzed for signs of activation by flow cytometry. Isolated peritoneal mast cell progenitors were studied before and after anti-IgE stimulation at single-cell level by time-lapse fluorescence microscopy. Lung mast cell progenitors were analyzed for their ability to produce IL-13 by intracellular flow cytometry in a mouse model of ovalbumin-induced allergic airway inflammation.Results: Sensitized mouse peritoneal mast cell progenitors demonstrate increased levels of phosphorylation of tyrosines on intracellular proteins (total tyrosine phosphorylation), and spleen tyrosine kinase (Syk) phosphorylation after antigen exposure. Anti-IgE induced cell surface-associated lysomal-associated membrane protein-1 (LAMP-1) in naive mast cell progenitors, and prompted loss of fluorescence signal and altered morphology of isolated cells loaded with lysotracker. In human mast cell progenitors, anti-IgE increased total tyrosine phosphorylation, cell surface-associated LAMP-1, and CD63. Lung mast cell progenitors from mice with ovalbumin-induced allergic airway inflammation produce IL-13.Conclusions: Mast cell progenitors become activated by IgE cross-linking and may contribute to the pathology associated with acute allergic airway inflammation.
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| 5. |
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| 6. |
- Salomonsson, Maya, et al.
(författare)
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Circulating mast cell progenitors correlate with reduced lung function in allergic asthma
- 2019
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Ingår i: Clinical and Experimental Allergy. - : Wiley. - 0954-7894 .- 1365-2222. ; 49:6, s. 874-882
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundStudies using mouse models have revealed that mast cell progenitors are recruited from the blood circulation to the lung during acute allergic airway inflammation. The discovery of a corresponding human mast cell progenitor population in the blood has enabled to study the relation of circulating mast cell progenitors in clinical settings.ObjectivesTo explore the possible association between the frequency of mast cell progenitors in the blood circulation and allergic asthma, we assessed the relation of this recently identified cell population with asthma outcomes and inflammatory mediators in allergic asthmatic patients and controls.MethodsBlood samples were obtained, and spirometry was performed on 38 well‐controlled allergic asthmatic patients and 29 controls. The frequency of blood mast cell progenitors, total serum IgE and 180 inflammation‐ and immune‐related plasma proteins were quantified.ResultsAllergic asthmatic patients and controls had a similar mean frequency of blood mast cell progenitors, but the frequency was higher in allergic asthmatic patients with reduced FEV1 and PEF (% of predicted) as well as in women. The level of fibroblast growth factor 21 (FGF‐21) correlated positively with the frequency of mast cell progenitors, independent of age and gender, and negatively with lung function. The expression of FcεRI on mast cell progenitors was higher in allergic asthmatic patients and correlated positively with the level of total IgE in the controls but not in the asthmatic patients.ConclusionElevated levels of circulating mast cell progenitors are related to reduced lung function, female gender and high levels of FGF‐21 in young adults with allergic asthma.
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| 7. |
- Wang, Juan, et al.
(författare)
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Asthma, allergic rhinitis and atopic dermatitis in association with home environment-The RHINE study br
- 2022
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Ingår i: SCIENCE OF THE TOTAL ENVIRONMENT. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 853
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Tidskriftsartikel (refereegranskat)abstract
- We studied home environment exposures in relation to asthma, allergic rhinitis and atopic dermatitis among offspringof participants (parents) in the Respiratory Health in Northern Europe (RHINE) study (age <= 30 y). Totally 17,881 off-spring from Iceland, Norway, Sweden, Denmark and Estonia were included. Home environment exposures, includingdampness and mold, type of dwelling, construction year and indoor painting were registered through a questionnaireanswered by parents in thefirst follow up (RHINE II). The parents reported ten years later with in the frame of RHINEIII offspring's birth year and offspring's asthma, allergic rhinitis, atopic dermatitis. They also reported dampness andmold at home from RHINE II to RHINE III. The prevalence of offspring's asthma before 10 y, asthma after 10 y, allergicrhinitis at any age and atopic dermatitis at any age were 9.7 %, 4.3 %, 15.6 % and 17.3 %, respectively. Asthma before10 y was related to any indoor painting at RHINE II (OR = 1.14, 95%CI (1.02, 1.29)). Asthmaafter 10 y was associatedwith dampness/mold at home (OR = 1.33-1.62) and living in the newest buildings (constructed in 1986-2001
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