| 1. |
- Islam, Rakibul, et al.
(författare)
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Combined blockade of complement C5 and TLR co-receptor CD14 synergistically inhibits pig-to-human corneal xenograft induced innate inflammatory responses
- 2021
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Ingår i: Acta Biomaterialia. - : Elsevier. - 1742-7061 .- 1878-7568. ; 127, s. 169-179
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Tidskriftsartikel (refereegranskat)abstract
- Inadequate supplies of donor corneas have evoked an escalating interest in corneal xenotransplantation. However, innate immune responses contribute significantly to the mechanism of xenograft rejection. We hypothesized that complement component C5 and TLR co-receptor CD14 inhibition would inhibit porcine cornea induced innate immune responses. Therefore, we measured cytokine release in human blood, induced by three forms of corneal xenografts with or without inhibitors. Native porcine cornea (NPC) induced interleukins (IL-1 beta, IL-2, IL-6, IL-8, IL-1ra), chemokines (MCP-1, MIP-1 alpha, MIP-1 beta) and other cytokines (TNF, G-CSF, INF-gamma, FGF-basic). Decellularized (DPC) and gamma-irradiated cornea (g-DPC) elevated the release of those cytokines. C5-blockade by eculizumab inhibited all the cytokines except G-CSF when induced by NPC. However, C5-blockade failed to reduce DPC and g-DPC induced cytokines. Blockade of CD14 inhibited DPC-induced cytokines except for IL-8, MCP-1, MIP-1 alpha, and G-CSF, while it inhibited all of them when induced by g-DPC. Combined blockade of C5 and CD14 inhibited the maximum number of cytokines regardless of the xenograft type. Finally, by using the TLR4 specific inhibitor Eritoran, we showed that TLR4 activation was the basis for the CD14 effect. Thus, blockade of C5, when combined with TLR4 inhibition, may have therapeutic potential in pig-to-human corneal xenotransplantation. Statement of significance Bio-engineered corneal xenografts are on the verge of becoming a viable alternative to allogenic human donor-cornea, but the host's innate immune response is still a critical barrier for graft acceptance. By overruling this barrier, limited graft availability would no longer be an issue for treating corneal diseases. We showed that the xenograft induced inflammation is initiated by the complement system and toll-like receptor activation. Intriguingly, the inflammatory response was efficiently blocked by simultaneously targeting bottleneck molecules in the complement system (C5) and the TLR co-receptor CD14 with pharmaceutical inhibitors. We postulate that a combination of C5 and CD14 inhibition could have a great therapeutic potential to overcome the immunologic barrier in pig-to-human corneal xenotransplantation. (C) 2021 The Authors. Published by Elsevier Ltd on behalf of Acta Materialia Inc.
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| 2. |
- Macpherson, Alex, et al.
(författare)
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The allosteric modulation of complement C5 by knob domain peptides
- 2021
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Ingår i: eLIFE. - : ELife Sciences Publications Ltd. - 2050-084X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Bovines have evolved a subset of antibodies with ultra-long heavy chain complementarity determining regions that harbour cysteine-rich knob domains. To produce high-affinity peptides, we previously isolated autonomous 3-6 kDa knob domains from bovine antibodies. Here, we show that binding of four knob domain peptides elicits a range of effects on the clinically validated drug target complement C5. Allosteric mechanisms predominated, with one peptide selectively inhibiting C5 cleavage by the alternative pathway C5 convertase, revealing a targetable mechanistic difference between the classical and alternative pathway C5 convertases. Taking a hybrid biophysical approach, we present C5-knob domain co-crystal structures and, by solution methods, observed allosteric effects propagating >50 angstrom from the binding sites. This study expands the therapeutic scope of C5, presents new inhibitors, and introduces knob domains as new, low molecular weight antibody fragments, with therapeutic potential.
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| 3. |
- Morgan, Rachael, et al.
(författare)
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Reduced physiological plasticity in a fish adapted to stable temperatures
- 2022
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - 0027-8424 .- 1091-6490. ; 119
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Tidskriftsartikel (refereegranskat)abstract
- Plasticity can allow organisms to maintain consistent performance across a wide range of environmental conditions. However, it remains largely unknown how costly plasticity is and whether a trade-off exists between plasticity and performance under optimal conditions. Biological rates generally increase with temperature, and to counter that effect, fish use physiological plasticity to adjust their biochemical and physiological functions. Zebrafish in the wild encounter large daily and seasonal temperature fluctuations, suggesting they should display high physiological plasticity. Conversely, laboratory zebrafish have been at optimal temperatures with low thermal fluctuations for over 150 generations. We treated this domestication as an evolution experiment and asked whether this has reduced the physiological plasticity of laboratory fish compared to their wild counterparts. We measured a diverse range of phenotypic traits, from gene expression through physiology to behavior, in wild and laboratory zebrafish acclimated to 15 temperatures from 10 °C to 38 °C. We show that adaptation to the laboratory environment has had major effects on all levels of biology. Laboratory fish show reduced plasticity and are thus less able to counter the direct effects of temperature on key traits like metabolic rates and thermal tolerance, and this difference is detectable down to gene expression level. Rapid selection for faster growth in stable laboratory environments appears to have carried with it a trade-off against physiological plasticity in captive zebrafish compared with their wild counterparts.
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| 4. |
- Sharifi, Sina, et al.
(författare)
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Sputter Deposition of Titanium on Poly(Methyl Methacrylate) Enhances Corneal Biocompatibility
- 2020
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Ingår i: Translational Vision Science & Technology. - : Association for Research in Vision and Ophthalmology. - 2164-2591. ; 9:13, s. 1-14
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To evaluate titanium (Ti) sputtering of the poly(methyl methacrylate) (PMMA) stem of the Boston Keratoprosthesis (BK) as a method to enhance interfacial adhesion between the PMMA and the recipient corneal tissue. Methods: PMMA specimens were plasma treated with Ar/O-2 and coated with Ti using a DC magnetron sputtering instrument. The topography and hydrophilicity of the surfaces were characterized using atomic force microscopy and a water contact angle instrument, respectively. Scratch hardness and adhesion of the Ti film were measured using a mechanical tester. Biocompatibility assessments were performed using cultured human corneal fibroblasts and whole blood ex vivo. The optical quality of the Ti sputtered BK was evaluated using a custom-made optical bench. Results: By contact angle studies, the Ti coating improved PMMA hydrophilicity to match that of medical-grade Ti (Ti-6Al-4V-ELI). Ti sputtering of contact surfaces resulted in a plate-like morphology with increased surface roughness, without impacting the transparency of the BK optical component. Scratch testing indicated that the mechanical behavior of the Ti coating was similar to that of casted Ti, and the coating was stable in pull-off adhesion testing. Sputtered Ti film was highly biocompatible based on tests of cell viability, adhesion, proliferation, differentiation, collagen deposition, and keratocan expression, the properties of which exceeded those of uncoated PMMA and did not induce increased complement activation. Conclusions: Titanium coating of the BK stem generated a mechanically and biologically favorable interface, which may help to enhance corneal stromal adhesion and biocompatibility. Translational Relevance: Improving the biocompatibility of the BK PMMA stem may improve long-term outcomes of implantation.
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| 5. |
- Sharifi, Sina, et al.
(författare)
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Tuning gelatin-based hydrogel towards bioadhesive ocular tissue engineering applications
- 2021
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Ingår i: Bioactive Materials. - : Elsevier. - 2452-199X. ; 6:11, s. 3947-3961
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Tidskriftsartikel (refereegranskat)abstract
- Gelatin based adhesives have been used in the last decades in different biomedical applications due to the excellent biocompatibility, easy processability, transparency, non-toxicity, and reasonable mechanical properties to mimic the extracellular matrix (ECM). Gelatin adhesives can be easily tuned to gain different viscoelastic and mechanical properties that facilitate its ocular application. We herein grafted glycidyl methacrylate on the gelatin backbone with a simple chemical modification of the precursor, utilizing epoxide ring-opening reactions and visible light-crosslinking. This chemical modification allows the obtaining of an elastic protein-based hydrogel (GELGYM) with excellent biomimetic properties, approaching those of the native tissue. GELGYM can be modulated to be stretched up to 4 times its initial length and withstand high tensile stresses up to 1.95 MPa with compressive strains as high as 80% compared to Gelatin-methacryloyl (GeIMA), the most studied derivative of gelatin used as a bioadhesive. GELGYM is also highly biocompatible and supports cellular adhesion, proliferation, and migration in both 2 and 3-dimensional cell-cultures. These characteristics along with its super adhesion to biological tissues such as cornea, aorta, heart, muscle, kidney, liver, and spleen suggest widespread applications of this hydrogel in many biomedical areas such as transplantation, tissue adhesive, wound dressing, bioprinting, and drug and cell delivery.
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| 6. |
- Zahl-Holmstad, Birgitte, et al.
(författare)
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Completeness of medication information in admission notes from emergency departments
- 2023
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Ingår i: BMC Health Services Research. - : BioMed Central (BMC). - 1472-6963. ; 23:1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundMedication lists prepared in the emergency department (ED) form the basis for diagnosing and treating patients during hospitalization. Since incomplete medication information may lead to patient harm, it is crucial to obtain a correct and complete medication list at hospital admission. In this cross-sectional retrospective study we wanted to explore medication information completeness in admission notes from Norwegian EDs and investigate which factors were associated with level of completeness.MethodsMedication information was assessed for completeness by applying five evaluation criteria; generic name, formulation, dose, frequency, and indication for use. A medication completeness score in percent was calculated per medication, per admission note and per criterion. Quantile regression analysis was applied to investigate which variables were associated with medication information completeness.ResultsAdmission notes for patients admitted between October 2018 and September 2019 and using at least one medication were included. A total of 1,080 admission notes, containing 8,604 medication orders, were assessed. The individual medications had a mean medication completeness score of 88.1% (SD 16.4), while admission notes had a mean medication completeness score of 86.3% (SD 16.2). Over 90% of all individual medications had information about generic name, formulation, dose and frequency stated, while indication for use was only present in 60%. The use of an electronic tool to prepare medication information had a significantly strong positive association with completeness. Hospital visit within the last 30 days, the patient's living situation, number of medications in use, and which hospital the patient was admitted to, were also associated with information completeness.ConclusionsMedication information completeness in admission notes was high, but potential for improvement regarding documentation of indication for use was identified. Applying an electronic tool when preparing admission notes in EDs seems crucial to safeguard completeness of medication information.
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| 7. |
- Zhu, Geyunjian Harry, et al.
(författare)
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Innate Immune Invisible Ultrasmall Gold Nanoparticles-Framework for Synthesis and Evaluation
- 2021
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 13:20, s. 23410-23422
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Tidskriftsartikel (refereegranskat)abstract
- Nanomedicine is seen as a potential central player in the delivery of personalized medicine. Biocompatibility issues of nanoparticles have largely been resolved over the past decade. Despite their tremendous progress, less than 1% of applied nanosystems can hit their intended target location, such as a solid tumor, and this remains an obstacle to their full ability and potential with a high translational value. Therefore, achieving immune-tolerable, blood-compatible, and biofriendly nanoparticles remains an unmet need. The translational success of nanoformulations from bench to bedside involves a thorough assessment of their design, compatibility beyond cytotoxicity such as immune toxicity, blood compatibility, and immune-mediated destruction/rejection/clearance profile. Here, we report a one-pot process-engineered synthesis of ultrasmall gold nanoparticles (uGNPs) suitable for better body and renal clearance delivery of their payloads. We have obtained uGNP sizes of as low as 3 nm and have engineered the synthesis to allow them to be accurately sized (almost nanometer by nanometer). The synthesized uGNPs are biocompatible and can easily be functionalized to carry drugs, peptides, antibodies, and other therapeutic molecules. We have performed in vitro cell viability assays, immunotoxicity assays, inflammatory cytokine analysis, a complement activation study, and blood coagulation studies with the uGNPs to confirm their safety. These can help to set up a long-term safety-benefit framework of experimentation to reveal whether any designed nanoparticles are immune-tolerable and can be used as payload carriers for next-generation vaccines, chemotherapeutic drugs, and theranostic agents with better body clearance ability and deep tissue penetration.
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| 8. |
- Andersson, Linnea, et al.
(författare)
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Storage of Transfusion Platelet Concentrates is Associated with Complement Activation and Reduced Ability of Platelets to Respond to Protease-Activated Receptor-1 and Thromboxane A2 Receptor
- 2024
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Ingår i: International Journal of Molecular Sciences. - : MDPI. - 1661-6596 .- 1422-0067. ; 25:2
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Tidskriftsartikel (refereegranskat)abstract
- Platelet activation and the complement system are mutually dependent. Here, we investigated the effects of storage time on complement activation and platelet function in routinely produced platelet concentrates. The platelet concentrates (n = 10) were stored at 22 degrees C for seven days and assessed daily for complement and platelet activation markers. Additionally, platelet function was analyzed in terms of their responsiveness to protease-activated receptor-1 (PAR-1) and thromboxane A2 receptor (TXA(2)R) activation and their capacity to adhere to collagen. Complement activation increased over the storage period for all analyzed markers, including the C1rs/C1-INH complex (fold change (FC) = 1.9; p < 0.001), MASP-1/C1-INH complex (FC = 2.0; p < 0.001), C4c (FC = 1.8, p < 0.001), C3bc (FC = 4.0; p < 0.01), and soluble C5b-9 (FC = 1.7, p < 0.001). Furthermore, the levels of soluble platelet activation markers increased in the concentrates over the seven-day period, including neutrophil-activating peptide-2 (FC = 2.5; p < 0.0001), transforming growth factor beta 1 (FC = 1.9; p < 0.001) and platelet factor 4 (FC = 2.1; p < 0.0001). The ability of platelets to respond to activation, as measured by surface expression of CD62P and CD63, decreased by 19% and 24% (p < 0.05) for PAR-1 and 69-72% (p < 0.05) for TXA(2)R activation, respectively, on Day 7 compared to Day 1. The extent of platelet binding to collagen was not significantly impaired during storage. In conclusion, we demonstrated that complement activation increased during the storage of platelets, and this correlated with increased platelet activation and a reduced ability of the platelets to respond to, primarily, TXA(2)R activation.
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| 9. |
- Asheim, Eirik R., et al.
(författare)
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Acute warming tolerance (CT max ) in zebrafish ( Danio rerio ) appears unaffected by changes in water salinity
- 2024
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Ingår i: PEERJ. - 2167-8359. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Tolerance against acute warming is an essential trait that can determine how organisms cope during heat waves, yet the mechanisms underlying it remain elusive. Water salinity has previously been suggested to modulate warming tolerance in fish and may therefore provide clues towards these limiting mechanisms. Here, using the critical thermal maximum (CTmax) test, we investigated whether short (2 hours) and long (10 days) term exposure to different water salinities (2 hours: 0-5 ppt, 10 days: 0-3 ppt) affected acute warming tolerance in zebrafish (N = 263). We found that water salinity did not affect the warming tolerance of zebrafish at either time point, indicating that salinity does not affect the mechanism limiting acute warming tolerance in zebrafish at these salinity ranges, and that natural fluctuations in salinity levels might not have a large impact on acute warming tolerance in wild zebrafish.
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| 10. |
- Chaban, Viktoriia, et al.
(författare)
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Escherichia coli-induced inflammatory responses are temperature-dependent in human whole blood ex vivo
- 2023
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Ingår i: Molecular Immunology. - : Elsevier. - 0161-5890 .- 1872-9142. ; 157, s. 70-77
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Tidskriftsartikel (refereegranskat)abstract
- Systemic inflammatory conditions are often associated with hypothermia or hyperthermia. Therapeutic hypothermia is used in post-cardiac arrest and some other acute diseases. There is a need for more knowledge concerning the effect of various temperatures on the acute inflammatory response. The complement system plays a crucial role in initiating the inflammatory response. We hypothesized that temperatures above and below the physiologic 37 & DEG;C affect complement activation and cytokine production ex vivo. Lepirudin-anticoagulated human whole blood from 10 healthy donors was incubated in the presence or absence of Escherichia coli at different temperatures (4 & DEG;C, 12 & DEG;C, 20 & DEG;C, 33 & DEG;C, 37 & DEG;C, 39 & DEG;C, and 41 & DEG;C). Complement activation was assessed by the terminal C5b-9 complement complex (TCC) and the alternative convertase C3bBbP using ELISA. Cytokines were measured using a 27-plex assay. Granulocyte and monocyte activation was evaluated by CD11b surface expression using flow cytometry. A consistent increase in complement activation was observed with rising temperature, reaching a maximum at 41 & DEG;C, both in the absence (C3bBbP p < 0.05) and presence (C3bBbP p < 0.05 and TCC p < 0.05) of E. coli. Temperature alone did not affect cytokine production, whereas incubation with E. coli significantly increased cytokine levels of IL-18, IL-2, IL-6, IL-8, IFN-& gamma;, and TNF at temperatures > 20 & DEG;C. Maximum increase occurred at 39 & DEG;C. However, a consistent decrease was observed at 41 & DEG;C, significant for IL-18 (p = 0.003). Granulocyte CD11b displayed the same temperature-dependent pattern as cytokines, with a corresponding increase in endothelial cell apoptosis and necrosis. Thus, blood temperature differentially determines the degree of complement activation and cytokine release.
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