| 1. |
- Ebrahimzadeh, PR, et al.
(författare)
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A subpopulation analysis of f-MLP stimulated granulocytes migrating in filters
- 1996
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Ingår i: Biorheology. - : IOS Press. - 0006-355X .- 1878-5034. ; 33:3, s. 231-250
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Tidskriftsartikel (refereegranskat)abstract
- Leukocyte migration in vitro has been studied extensively during many years without providing satisfactory theoretical models for the different migratory behaviors (chemotaxis and chemokinesis) of leukocyte populations. The present study utilized the fluid gradient chamber, which is a new method to study leukocyte migration in filters. Human neutrophils were applied between two stacked filters and migrated in all directions under the influence of constant concentrations or chemotactic gradients of f-MLP, maintained in fluid phase density gradients. The distributions of the granulocytes over filter depth were fitted to theoretical functions composed by 1-3 Gaussian distributions, representing subpopulations. The results showed that the neutrophils migrated as two discrete subpopulations during chemokinetic stimulation (a constant concentration of f-MLP). One of the subpopulations showed less active and passive (slow sedimentation under the influence of gravity) translocation. The most mobile subpopulation was divided into two new subpopulations when exposed to chemotactic stimulation (concentration gradient of f-MLP), one of which responded chemotactically and one of which migrated in random directions. The properties of the different subpopulations where characterized in terms of diffusion coefficient (random migration), convection velocity (chemotactic migration) and sedimentation coefficient (passive translocation).
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| 2. |
- Högfors-Rönnholm, Eva, et al.
(författare)
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Metagenomes and metatranscriptomes from boreal potential and actual acid sulfate soil materials
- 2019
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Ingår i: Scientific Data. - : Nature Publishing Group. - 2052-4463. ; 6, s. 1-6
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Tidskriftsartikel (refereegranskat)abstract
- Natural sulfide rich deposits are common in coastal areas worldwide, including along the Baltic Sea coast. When artificial drainage exposes these deposits to atmospheric oxygen, iron sulfide minerals in the soils are rapidly oxidized. This process turns the potential acid sulfate soils into actual acid sulfate soils and mobilizes large quantities of acidity and leachable toxic metals that cause severe environmental problems. It is known that acidophilic microorganisms living in acid sulfate soils catalyze iron sulfide mineral oxidation. However, only a few studies regarding these communities have been published. In this study, we sampled the oxidized actual acid sulfate soil, the transition zone where oxidation is actively taking place, and the deepest un-oxidized potential acid sulfate soil. Nucleic acids were extracted and 16S rRNA gene amplicons, metagenomes, and metatranscriptomes generated to gain a detailed insight into the communities and their activities. The project will be of great use to microbiologists, environmental biologists, geochemists, and geologists as there is hydrological and geochemical monitoring from the site stretching back for many years.
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