| 1. |
- Björses, Katarina, et al.
(author)
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In vitro and in vivo evaluation of chemically modified degradable starch microspheres for topical haemostasis
- 2011
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In: ACTA BIOMATERIALIA. - : Elsevier Science B.V. Amsterdam. - 1742-7061 .- 1878-7568. ; 7:6, s. 2558-2565
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Journal article (peer-reviewed)abstract
- Degradable starch microspheres (DSMs) are starch chains cross-linked with epichlorhydrin, forming glycerol-ether links. DSMs have been used for many years for temporary vascular occlusion and drug delivery in treatment of malignancies. They are also approved and used for topical haemostasis by absorbing excess fluid from the blood and concentrating endogenous coagulation factors, thereby facilitating haemostasis. This mechanism of action is not sufficient for larger bleedings in current chemical formulations of DSMs, and modification of DSMs to trigger activation of platelets or coagulation would be required for use in such applications. Chemical modifications of DSMs with N-octenyl succinic anhydride, chloroacetic acid, acetic anhydride, diethylaminoethyl chloride and ellagic acid were performed and evaluated in vitro with thrombin generation and platelet adhesion tests, and in vivo using an experimental renal bleeding model in rat. DSMs modified to activate platelets in vitro were superior in haemostatic capacity in vivo. Further studies with non-toxic substances are warranted to confirm these results and develop the DSM as a more effective topical haemostatic agent.
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| 2. |
- Andersson, Kristofer, et al.
(author)
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Mutations in COL1A1 and COL1A2 and dental aberrations in children and adolescents with osteogenesis imperfecta - A retrospective cohort study
- 2017
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In: PLOS ONE. - : PUBLIC LIBRARY SCIENCE. - 1932-6203. ; 12:5
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Journal article (peer-reviewed)abstract
- Osteogenesis imperfecta (OI) is a heterogeneous group of disorders of connective tissue, caused mainly by mutations in the collagen I genes (COL1A1 and COL1A2). Dentinogenesis imperfecta (DGI) and other dental aberrations are common features of OI. We investigated the association between collagen I mutations and DGI, taurodontism, and retention of permanent second molars in a retrospective cohort of 152 unrelated children and adolescents with OI. The clinical examination included radiographic evaluations. Teeth from 81 individuals were available for histopathological evaluation. COL1A1/2 mutations were found in 104 individuals by nucleotide sequencing. DGI was diagnosed clinically and radiographically in 29% of the individuals (44/152) and through isolated histological findings in another 19% (29/152). In the individuals with a COL1A1 mutation, 70% (7/10) of those with a glycine substitution located C-terminal of p. Gly305 exhibited DGI in both dentitions while no individual (0/7) with a mutation N-terminal of this point exhibited DGI in either dentition (p = 0.01). In the individuals with a COL1A2 mutation, 80% (8/10) of those with a glycine substitution located C terminal of p. Gly211 exhibited DGI in both dentitions while no individual (0/5) with a mutation N-terminal of this point (p = 0.007) exhibited DGI in either dentition. DGI was restricted to the deciduous dentition in 20 individuals. Seventeen had missense mutations where glycine to serine was the most prevalent substitution (53%). Taurodontism occurred in 18% and retention of permanent second molars in 31% of the adolescents. Dental aberrations are strongly associated with qualitatively changed collagen I. The varying expressivity of DGI is related to the location of the collagen I mutation. Genotype information may be helpful in identifying individuals with OI who have an increased risk of dental aberrations.
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| 3. |
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| 4. |
- Barbi, Florian, et al.
(author)
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Fungal ecological strategies reflected in gene transcription - a case study of two litter decomposers
- 2020
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In: Environmental Microbiology. - : Wiley. - 1462-2912 .- 1462-2920. ; 22, s. 1089-1103
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Journal article (peer-reviewed)abstract
- Microbial communities interplay with their environment through their functional traits that can be a response or an effect on the environment. Here, we explore how a functional trait-the decomposition of organic matter, can be addressed based on genetic markers and how the expression of these markers reflect ecological strategies of two fungal litter decomposer Gymnopus androsaceus and Chalara longipes. We sequenced the genomes of these two fungi, as well as their transcriptomes at different steps of Pinus sylvestris needles decomposition in microcosms. Our results highlighted that if the gene content of the two species could indicate similar potential decomposition abilities, the expression levels of specific gene families belonging to the glycoside hydrolase category reflected contrasting ecological strategies. Actually, C. longipes, the weaker decomposer in this experiment, turned out to have a high content of genes involved in cell wall polysaccharides decomposition but low expression levels, reflecting a versatile ecology compare to the more competitive G. androsaceus with high expression levels of keystone functional genes. Thus, we established that sequential expression of genes coding for different components of the decomposer machinery indicated adaptation to chemical changes in the substrate as decomposition progressed.
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| 5. |
- Barreto Henriksson, Helena, et al.
(author)
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Identification of Cell Proliferation Zones, Progenitor Cells and a Potential Stem Cell Niche in the Intervertebral Disc Region: A Study in Four Species.
- 2009
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In: SPINE. - 0362-2436. ; 34:21, s. 2278-2287
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Journal article (peer-reviewed)abstract
- STUDY DESIGN.: Descriptive experimental study in 4 different mammals. OBJECTIVE.: To investigate cell proliferation/regeneration and localize stem cells/progenitor cells within the intervertebral disc (IVD). SUMMARY OF BACKGROUND DATA.: Disc degeneration (DD) is believed to play a major role in patients with chronic lumbar pain. Lately, biologic treatment options for DD have gained increasing interest. Normal regeneration processes within the IVD and have previously been sparsely described and therefore it is of great interest to increase the knowledge about these processes. METHODS.: Detection of cell proliferations zones and label-retaining cells were done by in vivo 5-bromo-2-deoxyuridine (BrdU) labeling in 18 rabbits, killed after 4, 6, 10, 14, 28, or 56 days. Results were visualized with immunohistochemistry and fluorescence/confocal microscopy. Localization of progenitor cell were further investigated by immunohistochemistry using antibodies towards Notch1, Delta4, Jagged1, C-KIT, KI67, and Stro-1 in normal IVD from rabbits (n = 3), rats (n = 2), minipigs (n = 2), and in human degenerated IVD (n = 4). Further, flowcytometry analysis using progenitor markers were performed on additional human IVD cells (n = 3). RESULTS.: BrdU positive cells were found in comparable numbers at early and late time points in most regions of the anulus fibrosus (AF) and nucleus pulposus demonstrating slow ongoing cell proliferation. In the AF border to ligament zone (AFo) and the perichondriumregion (P) a stem cell niche-like pattern was determined (a high number of BrdU positive cells at early time points vs. only a few label retaining cells at later time points). In normal and DD tissue from the 4 investigated species progenitor cell markers were detected. CONCLUSION.: The IVD is a tissue with ongoing slow cell proliferation both in the AF and the nucleus pulposus. The stem cell niche pattern detected in AFo and P can be suggested to play a role for IVD morphology and function. These findings may be of importance for the development of biologic treatment strategies. PMID: 19755937 [PubMed - as supplied by publisher]
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| 6. |
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| 7. |
- Bigdeli, Narmin, 1974, et al.
(author)
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Adaptation of human embryonic stem cells to feeder-free and matrix-free culture conditions directly on plastic surfaces.
- 2008
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In: Journal of biotechnology. - : Elsevier BV. - 0168-1656. ; 133:1, s. 146-53
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Journal article (peer-reviewed)abstract
- Previous studies have shown that cultivation of undifferentiated human embryonic stem (hES) cells requires human fibroblasts (hF) or mouse embryonic fibroblast (mEF) feeders or a coating matrix such as laminin, fibronectin or Matrigeltrade mark in combination with mEF or hF conditioned medium. We here demonstrate a successful feeder-free and matrix-free culture system in which undifferentiated hES cells can be cultured directly on plastic surfaces without any supportive coating, in a hF conditioned medium. The hES cells cultured directly on plastic surfaces grow as colonies with morphology very similar to cells cultured on Matrigel(TM). Two hES cell lines SA167 and AS034.1 were adapted to matrix-free growth (MFG) and have so far been cultured up to 43 passages and cryopreserved successfully. The lines maintained a normal karyotype and expressed the expected marker profile of undifferentiated hES cells for Oct-4, SSEA-3, SSEA-4, TRA-1-60, TRA-1-81 and SSEA-1. The hES cells formed teratomas in SCID mice and differentiated in vitro into derivates of all three germ layers. Thus, the MFG-adapted hES cells appear to retain pluripotency and to remain undifferentiated. The present culture system has a clear potential to be scaleable up to a manufacturing level and become the preferred culture system for various applications such as cell therapy and toxicity testing.
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| 8. |
- Boberg, Johanna, et al.
(author)
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Decomposing capacity of fungi commonly detected in Pinus sylvestris needle litter
- 2011
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In: Fungal Ecology. - : Elsevier BV. - 1754-5048 .- 1878-0083. ; 4, s. 110-114
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Journal article (peer-reviewed)abstract
- A major part of the fungal community in coniferous litter consists of fungi whose taxonomic position and ecology are unknown. Here, nine isolates from within commonly occurring phylogenetic groups were tested for their ability to decompose Pinus sylvestris needles. In a 1-yr long incubation study, needle mass loss as well as changes in cellulose and lignin content were determined and compared to those caused by two litter basidiomycetes (Marasmius androsaceus and Mycena epipterygia) with recognized ability to decompose needles. A basidiomycetous Clavulina/Sistotrema strain appeared to be cellulolytic but not ligninolytic. Chalara longipes and three other strains within Helotiales also decomposed cellulose but not lignin, whereas Mollisia cinerea (also Helotiales) and two Dothideomycetes - Sydowia polyspora and a Mytilinidion sp., seemed unable to cause significant mass loss of cellulose. Lophodermium pinastri (Rhytismatales) readily decomposed cellulose, and also caused considerable loss of lignin. (C) 2010 Elsevier Ltd and The British Mycological Society. All rights reserved.
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| 9. |
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| 10. |
- Castaño Soler, Carles, et al.
(author)
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Optimized metabarcoding with Pacific biosciences enables semi-quantitative analysis of fungal communities
- 2020
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In: New Phytologist. - : Wiley. - 0028-646X .- 1469-8137. ; 228, s. 1149-1158
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Journal article (peer-reviewed)abstract
- Recent studies have questioned the use of high-throughput sequencing of the nuclear ribosomal internal transcribed spacer (ITS) region to derive a semi-quantitative representation of fungal community composition. However, comprehensive studies that quantify biases occurring during PCR and sequencing of ITS amplicons are still lacking. We used artificially assembled communities consisting of 10 ITS-like fragments of varying lengths and guanine-cytosine (GC) contents to evaluate and quantify biases during PCR and sequencing with Illumina MiSeq, PacBio RS II and PacBio Sequel I technologies. Fragment length variation was the main source of bias in observed community composition relative to the template, with longer fragments generally being under-represented for all sequencing platforms. This bias was three times higher for Illumina MiSeq than for PacBio RS II and Sequel I. All 10 fragments in the artificial community were recovered when sequenced with PacBio technologies, whereas the three longest fragments (> 447 bases) were lost when sequenced with Illumina MiSeq. Fragment length bias also increased linearly with increasing number of PCR cycles but could be mitigated by optimization of the PCR setup. No significant biases related to GC content were observed. Despite lower sequencing output, PacBio sequencing was better able to reflect the community composition of the template than Illumina MiSeq sequencing.
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