| 1. |
- Riba, Miquel, et al.
(författare)
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Darwin's wind hypothesis : does it work for plant dispersal in fragmented habitats?
- 2009
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Ingår i: New Phytologist. - : John Wiley & Sons. - 0028-646X .- 1469-8137. ; 183:3, s. 667-677
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Tidskriftsartikel (refereegranskat)abstract
- Using the wind-dispersed plant Mycelis muralis, we examined how landscape fragmentation affects variation in seed traits contributing to dispersal. Inverse terminal velocity () of field-collected achenes was used as a proxy for individual seed dispersal ability. We related this measure to different metrics of landscape connectivity, at two spatial scales: in a detailed analysis of eight landscapes in Spain and along a latitudinal gradient using 29 landscapes across three European regions. In the highly patchy Spanish landscapes, seed increased significantly with increasing connectivity. A common garden experiment suggested that differences in may be in part genetically based. The was also found to increase with landscape occupancy, a coarser measure of connectivity, on a much broader (European) scale. Finally, was found to increase along a south2013north latitudinal gradient. Our results for M. muralis are consistent with 'Darwin's wind dispersal hypothesis' that high cost of dispersal may select for lower dispersal ability in fragmented landscapes, as well as with the 'leading edge hypothesis' that most recently colonized populations harbour more dispersive phenotypes.
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| 2. |
- Sayols-Baixeras, Sergi, et al.
(författare)
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Streptococcus Species Abundance in the Gut Is Linked to Subclinical Coronary Atherosclerosis in 8973 Participants From the SCAPIS Cohort
- 2023
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Ingår i: Circulation. - : Lippincott Williams & Wilkins. - 0009-7322 .- 1524-4539. ; 148:6, s. 459-472
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Tidskriftsartikel (refereegranskat)abstract
- Background: Gut microbiota have been implicated in atherosclerotic disease, but their relation with subclinical coronary atherosclerosis is unclear. This study aimed to identify associations between the gut microbiome and computed tomography-based measures of coronary atherosclerosis and to explore relevant clinical correlates.Methods: We conducted a cross-sectional study of 8973 participants (50 to 65 years of age) without overt atherosclerotic disease from the population-based SCAPIS (Swedish Cardiopulmonary Bioimage Study). Coronary atherosclerosis was measured using coronary artery calcium score and coronary computed tomography angiography. Gut microbiota species abundance and functional potential were assessed with shotgun metagenomics sequencing of stool, and associations with coronary atherosclerosis were evaluated with multivariable regression models adjusted for cardiovascular risk factors. Associated species were evaluated for association with inflammatory markers, metabolites, and corresponding species in saliva.Results: The mean age of the study sample was 57.4 years, and 53.7% were female. Coronary artery calcification was detected in 40.3%, and 5.4% had at least 1 stenosis with >50% occlusion. Sixty-four species were associated with coronary artery calcium score independent of cardiovascular risk factors, with the strongest associations observed for Streptococcus anginosus and Streptococcus oralis subsp oralis (P<1×10-5). Associations were largely similar across coronary computed tomography angiography-based measurements. Out of the 64 species, 19 species, including streptococci and other species commonly found in the oral cavity, were associated with high-sensitivity C-reactive protein plasma concentrations, and 16 with neutrophil counts. Gut microbial species that are commonly found in the oral cavity were negatively associated with plasma indole propionate and positively associated with plasma secondary bile acids and imidazole propionate. Five species, including 3 streptococci, correlated with the same species in saliva and were associated with worse dental health in the Malmö Offspring Dental Study. Microbial functional potential of dissimilatory nitrate reduction, anaerobic fatty acid β-oxidation, and amino acid degradation were associated with coronary artery calcium score.Conclusions: This study provides evidence of an association of a gut microbiota composition characterized by increased abundance of Streptococcus spp and other species commonly found in the oral cavity with coronary atherosclerosis and systemic inflammation markers. Further longitudinal and experimental studies are warranted to explore the potential implications of a bacterial component in atherogenesis.
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| 3. |
- Sayols-Baixeras, Sergi, et al.
(författare)
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Streptococcus Species Abundance in the Gut Is Linked to Subclinical Coronary Atherosclerosis in 8973 Participants From the SCAPIS Cohort
- 2023
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Ingår i: Circulation. - : American Heart Association. - 0009-7322 .- 1524-4539. ; 148:6, s. 459-472
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Gut microbiota have been implicated in atherosclerotic disease, but their relation with subclinical coronary atherosclerosis is unclear. This study aimed to identify associations between the gut microbiome and computed tomography–based measures of coronary atherosclerosis and to explore relevant clinical correlates.METHODS: We conducted a cross-sectional study of 8973 participants (50 to 65 years of age) without overt atherosclerotic disease from the population-based SCAPIS (Swedish Cardiopulmonary Bioimage Study). Coronary atherosclerosis was measured using coronary artery calcium score and coronary computed tomography angiography. Gut microbiota species abundance and functional potential were assessed with shotgun metagenomics sequencing of fecal samples, and associations with coronary atherosclerosis were evaluated with multivariable regression models adjusted for cardiovascular risk factors. Associated species were evaluated for association with inflammatory markers, metabolites, and corresponding species in saliva.RESULTS: The mean age of the study sample was 57.4 years, and 53.7% were female. Coronary artery calcification was detected in 40.3%, and 5.4% had at least 1 stenosis with >50% occlusion. Sixty-four species were associated with coronary artery calcium score independent of cardiovascular risk factors, with the strongest associations observed for Streptococcus anginosus and Streptococcus oralis subsp oralis (P<1×10–5). Associations were largely similar across coronary computed tomography angiography–based measurements. Out of the 64 species, 19 species, including streptococci and other species commonly found in the oral cavity, were associated with high-sensitivity C-reactive protein plasma concentrations, and 16 with neutrophil counts. Gut microbial species that are commonly found in the oral cavity were negatively associated with plasma indole propionate and positively associated with plasma secondary bile acids and imidazole propionate. Five species, including 3 streptococci, correlated with the same species in saliva and were associated with worse dental health in the Malmö Offspring Dental Study. Microbial functional potential of dissimilatory nitrate reduction, anaerobic fatty acid β-oxidation, and amino acid degradation were associated with coronary artery calcium score.CONCLUSIONS: This study provides evidence of an association of a gut microbiota composition characterized by increased abundance of Streptococcus spp and other species commonly found in the oral cavity with coronary atherosclerosis and systemic inflammation markers. Further longitudinal and experimental studies are warranted to explore the potential implications of a bacterial component in atherogenesis.
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| 4. |
- Sennerby, Lars, 1960, et al.
(författare)
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A morphometric and biomechanic comparison of titanium implants inserted in rabbit cortical and cancellous bone.
- 1992
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Ingår i: The International journal of oral & maxillofacial implants. - 0882-2786. ; 7:1, s. 62-71
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Tidskriftsartikel (refereegranskat)abstract
- The removal torques for screw-shaped pure titanium implants inserted in rabbit tibia and the femoral part of the knee joint and the tissue response to these implants, as quantitated with light microscopic morphometry on ground sections, were compared after 6 weeks, 3 months, and 6 months. The bone surrounding the femoral intra-articular implants was mostly cancellous, while cortical bone was formed around the tibial implants. The torque needed to remove the intra-articular implants increased with time, but there was no such increase for the tibial implants. At 6 weeks, significantly less torque was needed to remove the intra-articular implants in spite of the fact that significantly more bone was found in the threads of these implants as compared with the tibial implants. When calculating the amount of bone in threads situated in the cortical and subchondral passage, more was found in the threads of the tibial implants, which corresponded to the higher removal torque. Additional light microscopic observations on implants unscrewed after 12 months in rabbit tibia indicated that rupture occurred between the implant surface and calcified bone. Findings indicate that the resistance to unscrewing is dependent on the amount of compact bone surrounding a titanium implant.
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| 5. |
- Sennerby, Lars, 1960, et al.
(författare)
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Activation and migration of leukocytes and vascular leakage induced by serum-opsonized zymosan particles in hamster cheek pouch.
- 1989
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Ingår i: Inflammation. - : Springer Science and Business Media LLC. - 0360-3997 .- 1573-2576. ; 13:1, s. 91-102
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Tidskriftsartikel (refereegranskat)abstract
- The effect of topically applied serum-opsonized zymosan (SOZ) and zymosan-activated serum (ZAS) was studied in the hamster cheek pouch. Our data suggest that early vascular leakage, evaluated by intravital fluorescence microscopy after injection of FITC-dextran, and accumulation of polymorphonuclear granulocytes (PMNGs), quantitated in fixed whole tissue specimens, induced by ZAS and SOZ were caused by complement activation, whereas the late leakages (greater than 20 min after SOZ application) was PMNG-dependent. Inhibition of prostaglandin and leukotriene synthesis by indomethacin, nordihydroguaiaretic acid (NDGA), and BW755C influence early and late vascular leakage as well as accumulation of PMNGs. These drugs also inhibited the activation of hamster PMNGs in vitro, as evaluated by chemiluminescence, in a dose-dependent manner. (-)-Terbutaline, an adrenergic beta agonist, decreased vascular leakage but had no effect on PMNG activation and accumulation.
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| 6. |
- Sennerby, Lars, 1960, et al.
(författare)
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Structure of the bone-titanium interface in retrieved clinical oral implants.
- 1991
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Ingår i: Clinical oral implants research. - : Wiley. - 0905-7161. ; 2:3, s. 103-11
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Tidskriftsartikel (refereegranskat)abstract
- 7 clinically stable, "osseointegrated", titanium implants, inserted in human jaws for 1-16 years, were retrieved for morphological analysis of the bone-titanium interface, using 3 different preparation techniques. The bone-titanium interface varied as judged from light microscopy of ground sections. The threads of the implants were well filled (79-95%) with dense lamellar bone as quantified with morphometry. A large fraction of the implant surface (56-85%) appeared to be in direct contact with the mineralized bone. In general, the non-bone areas consisted of pockets with osteocytes, bone marrow tissue and/or vessels. Sections were prepared for light microscopy and transmission electron microscopy using a fracture technique, where the implant was separated from the embedded tissue before sectioning, and an electropolishing technique, where the bulk part of the implant was electrochemically removed. In areas judged as direct mineralized bone-titanium contact in the light microscope, the interfacial structure varied at the ultrastructural level. In areas along the interface, unmineralized tissue was present either as a narrow 0.5-1 micron wide zone containing collagen fibril or as deeper pockets containing osteocytes or vessels. In areas with mineralized bone contact, an amorphous granular layer (100-400 nm wide) with no mineral was observed in the innermost interface bordering the mineralized bone, with an electron-dense lamina limitans-like line (approximately 50 nm thick). It is concluded that the bone-titanium interface of the 7 clinically retrieved titanium oral implants examined in the present study bone was heterogenous. In areas of a direct mineralized bone-titanium contact at the ultrastructural level, mineralized bone reached close to the implant surface, but was separated by an amorphous layer, being 100-400 nm thick.
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| 7. |
- Thomsen, Peter, et al.
(författare)
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Implants in the abdominal wall of the rat
- 1986
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Ingår i: Scandinavian Journal of Plastic and Reconstructive Surgery. - : Informa UK Limited. - 0036-5556. ; 20:2, s. 173-182
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Tidskriftsartikel (refereegranskat)abstract
- An experimental model is presented that allows qualitative as well as quantitative studies of the soft tissue response to implant materials used in reconstructive surgery. Plugs of non-alloyed titanium and polymers (Teflon, Delrin) were inserted into the abdominal wall of rats, with a portion of the plug penetrating through the peritoneum into the abdominal cavity. The tissue reaction was evaluated by means of light and electron microscopy for up to 9 weeks after insertion. Titanium implants were in direct contact with the connective tissue without intervening inflammatory cells. The defect in the peritoneum was sealed by a close apposition of the mesothelial membrane to the titanium surface and no connective tissue surrounded the intra-peritoneal portion of the plug. In contrast, a fibrous capsule surrounded the intra-peritoneal portion of Teflon and Delrin implants. A reactive zone consisting of active macrophages and giant cells was present at the surface of these implants separating the implant from the surrounding fibrous capsule. This study shows that the tissue response at the interface to foreign materials can be studied using light and electron microscopic techniques and that profound differences in tissue response exist between different materials.
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| 8. |
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| 9. |
- Akselsson, Roland, et al.
(författare)
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Fysikaliska faktorer
- 1994
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Ingår i: Arbete Människa Teknik. - 9175224143 ; , s. 45-113
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 10. |
- Akselsson, Roland, et al.
(författare)
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Fysikaliska faktorer
- 2005
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Ingår i: Arbete Människa Teknik. - 9175228955 ; , s. 45-113
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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