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- Johansson, Maria A., 1981-
(författare)
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Infant gut microbiota, immune responses and allergic disease during childhood
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The early-life microbiota is important for postnatal immune maturation and implied in immune mediated diseases. The aim of this work was to study specific species of bacteria in the gut microbiota and relate them to immune function and allergic disease during childhood.In paper I we investigated gut bacteria in feces from infants included in a prospective allergy cohort. We found that children with non-allergic parents were more likely to be colonized with a group of lactobacilli. Further, lactobacilli colonization was more prevalent in children remaining non-allergic, regardless of allergic heredity. In paper II we related the infant gut bacteria to immune function at two years of age. Infant Staphylococcus (S.) aureus colonization associated with increased immune responsiveness, whereas co-colonization with S. aureus and lactobacilli associated with reduced responses. In paper III we investigated T regulatory (Treg) cell phenotype and cytokine production during childhood, and related S. aureus and lactobacilli colonization to Treg phenotype at the age of two. The Treg population matured with age, regarding phenotype and cytokine production. Furthermore, infant S. aureus colonization associated with Treg phenotype at the age of two. In paper IV we investigated the in vitro peripheral blood mononuclear cells responses to soluble factors produced by lactobacilli and S. aureus. Both T- and natural killer cells responded with cytokine production, degranulation and proliferation after S. aureus and simultaneous culture with lactobacilli could dampen the S. aureus-induced responses.Taken together this thesis shows that the gut microbiota is altered in children who develop allergies, and that early life bacteria associate with immune function. Our in vitro findings support that lactobacilli modulate immune maturation and responses, and that early lactobacilli-colonization may be important for a properly regulated maturation of the immune system.
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| 2. |
- Tebano Ahlquist, Eva-Maria, 1955-
(författare)
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Skolans levda rum och lärandets villkor : Meningsskapande i montessoriskolans fysiska miljö
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This study examines the school’s physical environment as a place of learning, and takes its starting point in the phenomenology movement, inspired both by Merleau-Ponty’s thesis of man’s physical relation to the world and by the existential analysis represented by Heidegger which implies a mutual relationship between man and the world.Such a view rejects a standpoint which describes man as being divided between a material body and a thinking soul. Instead, there emerges an embodied self which engages in meaningful interaction with its surroundings. The choice of this standpoint has implications for the design of the school’s physical environment. Montessori pedagogy is one of the activity-based pedagogies which have designed the physical environment in line with this theory. The purpose of the study is to understand, but further to visualise, the way in which the conditions for learning for children and adolescents are created in schools, from pre-school to lower secondary level, which follow the Montessori pedagogy. The material for the empirical study has been gathered from Europe and the US and from differing social contexts. The reason for this is to discover what distinguishes the prepared environment. The study also discusses the way in which the argument for a form of schooling which is based on activity, from the early 20th century to the present day, has been addressed through the architectural design of schools.The thesis shows that the rich array of didactic material in the schools observed offers pupils the opportunity to perform activities which create meaning. The organisation of the environment provides the pupils with the necessary conditions to concentrate fully on their work and to complete their tasks without interruption. I see the didactic continuity which prevails from pre-school to the lower secondary school in the Montessori schools studied as a prerequisite if the pedagogical activity is to offer meaning and create the conditions for learning in the way demonstrated by the empirical studies.
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| 3. |
- Yuan, Bo, 1985-, et al.
(författare)
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Polychlorinated alkanes in paired blood serum and breast milk in a Swedish cohort study : Matrix dependent partitioning differences compared to legacy POPs
- 2024
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Ingår i: Environment International. - : Elsevier. - 0160-4120 .- 1873-6750. ; 183
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Polychlorinated alkanes (PCAs) constitute a large group of individual congeners originating from commercial chlorinated paraffin (CP) products with carbon chain lengths of PCAs-C10-13, PCAs-C14-17, and PCAs-C18-32, occasionally containing PCAs-C6-9 impurities. The extensive use of CPs has led to global environmental pollution of PCAs. This study aimed to quantify PCAs in paired serum and breast milk of lactating Swedish mothers, exploring their concentration relationship.METHODS: Twenty-five paired samples of mothers' blood serum and breast milk were analysed and concentrations were determined for PCAs C6-32 and compared to 4,4'-DDE, the PCB congener 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153), and hexachlorobenzene (HCB).RESULTS: The median concentrations of PCAs-C6-9, PCAs-C10-13, PCAs-C14-17, PCAs-C18-32 and ΣPCAs in serum were 14, 790, 520, 16 and 1350 ng/g lipid weight (lw), respectively, and in breast milk 0.84, 36, 63, 6.0 and 107 ng/g lw. Levels of 4,4'-DDE, CB-153 and HCB were comparable in the two matrices, serum and breast milk at 17, 12 and 4.9 ng/g lw. The results show significant differences of PCAs-C10-13 and PCAs-C14-17 in breast milk with 22- and 6.2-times lower lw-based concentrations than those measured in serum. On wet weight the differences serum/breast milk ratios of PCAs-C6-9, PCAs-C10-13, PCAs-C14-17, PCAs-C18-32 and ΣPCAs were 1.7, 3.2, 1.0, 0.4 and 1.6, respectively, while the ratio for 4,4'-DDE, CB-153 and HCB were each close to 0.1.CONCLUSION: Swedish lactating mothers had high serum concentrations of PCAs-C10-13 and PCAs-C14-17, with the ΣPCAs median serum concentration of 1350 ng/g lw. The breast milk concentration, although considerably lower at 107 ng/g lw, still surpassed those of 4,4'-DDE, CB-153 and HCB, suggesting an exposure risk of infants to PCAs. The variation in blood and breast milk accumulation between PCAs and studied legacy POPs, is rarely discussed but warrants further studies on partitioning properties as well as associated toxicological implications.
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