Suoturvelisäyksen typpivaikutuksesta humusköyhässä savimaassa

vKirjasto Aj-

Electroencapsulation of Mesoporous Silicon Particles for Controlled Oral Drug Delivery

Mesoporous silicon (PSi) has lately been the focus of interest as a potential new orally dosed drug carrier in a steeply increasing number of papers, where the strengths of PSi in such applications has been shown. Perhaps most importantly, drugs will remain in an amorphous form instead of crystallizing while loaded into the pores of PSi. The advantage of this is greatly increased solubility and dissolution rate of the drug. In the present work, we investigate the possibility of enhancing the drug carrier functionality of PSi micro- and nanoparticles by encapsulating the drug loaded PSi particles in a suitable polymer capsule structure by the method of collision of oppositely charged, electrosprayed droplets. Embed-ding the PSi particles in such polymer structure of micrometer scale will not only vastly im-prove the workability of PSi nanoparticles and the smallest of microparticles, but with suit-able material choices will also potentially enable targeted release of the drug loaded PSi par-ticles to a desired part of the gastrointestinal (GI) tract. This would help towards eliminating the intestinal first-pass effect of an orally dosed drug, which together with the already advan-tageous properties of PSi would result in an increased bioavailability of the drug. The gained advantage would be significant, since it has been estimated that more than 95% of new drug candidates suffer from poor pharmacokinetic properties, resulting in poor bioavailability.</p

Plankton metabolism and sedimentation in a small boreal lake — a long-term perspective

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Altered Mucosal-Associated Invariant T Cells Phenotype in Children with Newly Diagnosed Type 1 Diabetes but not in Autoantibody-Positive At-Risk Children

Introduction: Mucosal-associated invariant T (MAIT) cells are unconventional T cells, enriched in the gut. They express an invariant T-cell receptor and recognize riboflavin metabolites from bacteria presented by MHC-Ib-related protein 1 (MR1) molecules. Alterations in gut microbiota have been reported in patients with type 1 diabetes (T1D), even before the onset of the disease. These changes can potentially alter the frequency or phenotype of circulating MAIT cells. Methods: We characterized peripheral blood MAIT cells in a cohort of 51 children with newly diagnosed T1D, 27 at-risk children positive for multiple autoantibodies (AAb+) and 113 age-matched healthy children. Using multi-colour flow cytometry, we analysed the frequency, surface phenotype and cytokine production of MAIT cells. In addition, we characterized the frequency and surface phenotype of blood MAIT cells in 26 patients with long-standing T1D and 25 age-matched healthy controls. Results: No significant differences in MAIT cell frequency were observed between the study groups. Further phenotyping revealed that the expression of CD8, CD27, CCR5 and β7 integrin on MAIT cells was lower in children with newly diagnosed T1D compared to AAb+ and healthy children. The frequency of MAIT cells producing IFN-γ was also lower in children with newly diagnosed T1D, but the frequencies of IL-17A- and IL-4-secreting MAIT cells were similar in the study groups. Finally, the capacity of MAIT cells to be activated in vitro by E.coli bacteria through MR1 was comparable between the study groups. However, none of these changes was observed in adult patients with long-standing T1D. In contrast, a decreased frequency of MAIT cells and increased CD25 expression was observed in adult T1D patients with a short duration after diagnosis. Conclusion: There are subtle changes in the circulating MAIT compartment in patients with T1D at the onset of the disease as well as after clinical diagnosis, but not in AAb+ at-risk subjects including progression to clinical disease. Consequently, the alterations in blood MAIT cells are likely associated with the clinical manifestation of the disease rather than being features of earlier T1D autoimmunity

Mucosal-associated invariant T cell alterations during the development of human type 1 diabetes

Aims/hypothesis Mucosal-associated invariant T (MAIT) cells are innate-like T cells that recognise derivatives of bacterial riboflavin metabolites presented by MHC-Ib-related protein 1 (MR1) molecules and are important effector cells for mucosal immunity. Their development can be influenced by the intestinal microbiome. Since the development of type 1 diabetes has been associated with changes in the gut microbiome, this can be hypothesised to lead to alterations in circulating MAIT cells. Accordingly, peripheral blood MAIT cell alterations have been reported previously in patients with type 1 diabetes. However, a comprehensive analysis of the frequency and phenotype of circulating MAIT cells at different stages of type 1 diabetes progression is currently lacking. Methods We analysed the frequency, phenotype and functionality of peripheral blood MAIT cells, as well as gamma delta T cells, invariant natural killer T (iNKT) cells and natural killer (NK) cells with flow cytometry in a cross-sectional paediatric cohort (aged 2-15) consisting of 51 children with newly diagnosed type 1 diabetes, 27 autoantibody-positive (AAb(+)) at-risk children, and 113 healthy control children of similar age and HLA class II background. The frequency of MAIT cells was also assessed in a separate cross-sectional adult cohort (aged 19-39) of 33 adults with established type 1 diabetes and 37 healthy individuals of similar age. Results Children with newly diagnosed type 1 diabetes displayed a proportional increase of CD8(-)CD27(-)MAIT cells compared with healthy control children (median 4.6% vs 3.1% of MAIT cells, respectively, p = 0.004), which was associated with reduced expression of C-C chemokine receptor (CCR)5 (median 90.0% vs 94.3% of MAIT cells, p = 0.02) and beta 7 integrin (median 73.5% vs 81.7% of MAIT cells, p = 0.004), as well as decreased production of IFN-gamma (median 57.1% vs 69.3% of MAIT cells, p = 0.04) by the MAIT cells. The frequency of MAIT cells was also decreased in AAb(+)children who later progressed to type 1 diabetes compared with healthy control children (median 0.44% vs 0.96% of CD3(+)T cells, p = 0.04), as well as in adult patients with a short duration of type 1 diabetes (less than 6 years after diagnosis) compared with control individuals (median 0.87% vs 2.19% of CD3(+)T cells, p = 0.007). No alterations in gamma delta T cell, iNKT cell or NK cell frequencies were observed in children with type 1 diabetes or in AAb(+) children, with the exception of an increased frequency of IL-17A(+)gamma delta T cells in children with newly diagnosed diabetes compared with healthy control children (median 1.58% vs 1.09% of gamma delta T cells, p = 0.002). Conclusions/interpretation Changes in the frequency and phenotype of circulating MAIT cells were detectable before, at the onset and after diagnosis of type 1 diabetes in cross-sectional cohorts. Our results suggest a possible temporal association between peripheral blood MAIT cell alterations and the clinical onset of type 1 diabetes.Peer reviewe

Responses of zooplankton to long-term environmental changes in a small boreal lake

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