| 1. |
- Sinnhuber, M., et al.
(författare)
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Heppa III Intercomparison Experiment on Electron Precipitation Impacts : 2. Model-Measurement Intercomparison of Nitric Oxide (NO) During a Geomagnetic Storm in April 2010
- 2022
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Ingår i: Journal of Geophysical Research - Space Physics. - 2169-9380 .- 2169-9402. ; 127:1
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Tidskriftsartikel (refereegranskat)abstract
- Precipitating auroral and radiation belt electrons are considered to play an important part in the natural forcing of the middle atmosphere with a possible impact on the climate system. Recent studies suggest that this forcing is underestimated in current chemistry-climate models. The HEPPA III intercomparison experiment is a collective effort to address this point.In this study, we apply electron ionization rates from three data-sets in four chemistry-climate models during a geomagnetically active period in April 2010. Results are evaluated by comparison with observations of nitric oxide (NO) in the mesosphere and lower thermosphere. Differences between the ionization rate data-sets have been assessed in a companion study. In the lower thermosphere, NO densities differ by up to one order of magnitude between models using the same ionization rate data-sets due to differences in the treatment of NO formation, model climatology, and model top height. However, a good agreement in the spatial and temporal variability of NO with observations lends confidence that the electron ionization is represented well above 80 km. In the mesosphere, the averages of model results from all chemistry-climate models differ consistently with the differences in the ionization-rate data-sets, but are within the spread of the observations, so no clear assessment on their comparative validity can be provided. However, observed enhanced amounts of NO in the mid-mesosphere below 70 km suggest a relevant contribution of the high-energy tail of the electron distribution to the hemispheric NO budget during and after the geomagnetic storm on April 6.
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| 2. |
- Vilkuna-Rautiainen, T, et al.
(författare)
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Serum antibody response to periodontal pathogens and herpes simplex virus in relation to classic risk factors of cardiovascular disease.
- 2006
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Ingår i: International Journal of Epidemiology. - : Oxford University Press (OUP). - 0300-5771 .- 1464-3685. ; 35:6, s. 1486-1494
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Increasing evidence links chronic infections, especially burden of several infections, with increased risk for cardiovascular diseases (CVD). We studied joint immune response against two major periodontal pathogens and herpes simplex virus (HSV) in relation to established risk factors of CVD. METHODS: Serum antibody levels to HSV, Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis were determined by ELISA. The study included 1107 subjects, 734 from Finland and 373 from Russia. RESULTS: Combined antibody response to periodontal pathogens was associated inversely (OR, 95% CI) with high-density lipoprotein (HDL) cholesterol concentration (beta = 0.35; 0.20, 0.60; P < 0.001) and directly with HSV antibody quartiles: compared with the first quartile, ORs (95% CI) for quartiles 2-4 were 1.43 (0.88-2.32), 1.74 (1.07-2.82), and 1.89 (1.18-3.02), respectively (P for trend <0.001), after adjusting for age, gender, area, education, smoking, BMI, alcohol, triglycerides, and number of teeth. In linear regression analysis, the 3-pathogen antibody score (comprising antibody levels against periodontal pathogens and HSV) was inversely associated with HDL cholesterol concentration (beta = -0.067/1 mmol/l; -0.235, -0.018; P < 0.05). CONCLUSIONS: HSV infection may promote infection by periodontal pathogens. Furthermore, the infectious burden comprising HSV and periodontitis may increase the risk for CVD by clearly decreasing HDL cholesterol concentrations.
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| 3. |
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| 4. |
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| 5. |
- Oittinen, J, et al.
(författare)
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Periodontal disease and bacterial vaginosis increase the risk for adverse pregnancy outcome.
- 2005
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Ingår i: Infectious diseases in obstetrics and gynecology. - 1064-7449 .- 1098-0997. ; 13:4, s. 213-216
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To determine whether periodontal disease or bacterial vaginosis (BV) diagnosed before pregnancy increase the risk for adverse pregnancy outcome. METHODS: We enrolled a total of 252 women who had discontinued contraception in order to become pregnant. The first 130 pregnant women were included in the analyses. RESULTS: Multivariate analysis showed a strong association between periodontal disease and adverse pregnancy outcome (OR 5.5, 95% confidence interval 1.4-21.2; p = 0.014), and a borderline association between BV and adverse pregnancy outcome (OR 3.2, 95% confidence interval 0.9-10.7; p = 0.061). CONCLUSION: Our study suggests that pre-pregnancy counseling should include both oral and vaginal examinations to rule out periodontal disease and BV. This may ultimately have an impact on antenatal healthcare, and decrease the risk for adverse pregnancy outcome.
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| 6. |
- Pussinen, PJ, et al.
(författare)
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Periodontitis decreases the antiatherogenic potency of high density lipoprotein.
- 2004
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Ingår i: Journal of Lipid Research. - 0022-2275 .- 1539-7262. ; 45:1, s. 139-147
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Tidskriftsartikel (refereegranskat)abstract
- Periodontitis, a consequence of persistent bacterial infection and chronic inflammation, has been suggested to predict coronary heart disease (CHD). The aim of this study was to investigate the impact of periodontitis on HDL structure and antiatherogenic function in cholesterol efflux in vitro. HDL was isolated from 30 patients (age 43.6 +/- 6.1 years, mean +/- SD) with periodontitis before and after (3.2 +/- 1.4 months) periodontal treatment. The capacity of HDL for cholesterol efflux from macrophages (RAW 264.7), HDL composition, and key proteins of HDL metabolism were determined. After periodontal treatment, phospholipid transfer protein (PLTP) activity was 6.2% (P<0.05) lower, and serum HDL cholesterol concentration, PLTP mass, and cholesteryl ester transfer protein activity were 10.7% (P<0.001), 7.1% (P=0.078), and 19.4% (P<0.001) higher, respectively. The mean HDL2/HDL3 ratio increased from 2.16 +/- 0.87 to 3.56 +/- 0.48 (P<0.05). HDL total phospholipid mass and sphingomyelin-phosphatidylcholine ratio were 7.4% (P<0.05) and 36.8% (P<0.001) higher, respectively. The HDL-mediated cholesterol efflux tended to be higher after periodontal treatment; interestingly, this increase was significant (P<0.05) among patients whose C-reactive protein decreased (53.7% reduction, P=0.015) and who were positive by PCR for Actinobacillus actinomycetemcomitans. These results suggest that periodontitis causes similar, but milder, changes in HDL metabolism than those that occur during the acute-phase response and that periodontitis may diminish the antiatherogenic potency of HDL, thus increasing the risk for CHD.
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| 7. |
- Pussinen, PJ, et al.
(författare)
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Severe periodontitis enhances macrophage activation via increased serum lipopolysaccharide.
- 2004
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Ingår i: Arteriosclerosis, Thrombosis and Vascular Biology. - 1079-5642 .- 1524-4636. ; 24:11, s. 2174-2180
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: In periodontitis, overgrowth of Gram-negative bacteria and access of lipopolysaccharide (LPS) to circulation may activate macrophages leading to foam cell formation. We investigated whether periodontal treatment affects proatherogenic properties of low-density lipoprotein (LDL) and, thus, macrophage activation. METHODS AND RESULTS: LDL was isolated and characterized before and after treatment from 30 systemically healthy patients with periodontitis. Production of cytokines and LDL cholesteryl ester (LDL-CE) uptake by macrophages (RAW 264.7) was determined. Baseline periodontal variables correlated positively with serum LPS and C-reactive protein concentrations, as well as macrophage cytokine production and LDL-CE uptake. LPS concentration correlated positively with serum concentration of oxidized LDL and cytokine production. Higher cytokine production and LDL-CE uptake were induced by LDL isolated from patients with elevated number of affected teeth before treatment. Patients with serum LPS concentrations above the median (0.87 ng/mL) at baseline had higher serum high-density lipoprotein (HDL) cholesterol (baseline versus after treatment, 1.30+/-0.19 versus 1.48+/-0.28 mmol/L; P=0.002) and HDL/LDL ratio (0.31+/-0.01 versus 0.34+/-0.10; P=0.048), but lower serum LPS concentration (1.70+/-0.49 versus 0.98+/-0.50 ng/mL; P=0.004) and autoantibodies to beta2-glycoprotein I (0.11+/-0.06 versus 0.09+/-0.04 ELISA units; P=0.022) after treatment. CONCLUSIONS: Our results suggest that in systemically healthy patients, the infected/inflamed area in periodontitis is associated with macrophage activation via increased serum LPS concentration.
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| 8. |
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| 9. |
- Lakio, L, et al.
(författare)
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Actinobacillus actinomycetemcomitans serotype d-specific antigen contains the O antigen of lipopolysaccharide.
- 2003
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Ingår i: Infection and Immunity. - 0019-9567 .- 1098-5522. ; 71:9, s. 5005-5011
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Tidskriftsartikel (refereegranskat)abstract
- Actinobacillus actinomycetemcomitans is a gram-negative, facultatively anaerobic bacterium which is associated especially with aggressive forms of periodontitis. Contradictory results on the localization of the A. actinomycetemcomitans serotype-specific antigen have been reported. The aim of the present study was to characterize the A. actinomycetemcomitans serotype d-specific antigen. The antigen was isolated by affinity chromatography. The affinity column was prepared from immunoglobulin G isolated from rabbit antiserum raised against A. actinomycetemcomitans serotype d. The isolated antigen was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Western blotting, and silver staining, all of which revealed a ladder-like structure typical for the O antigen of lipopolysaccharide (LPS). In a displacement enzyme-linked immunosorbent assay (ELISA), the isolated antigen displaced in a concentration-dependent manner the binding of the polyclonal rabbit antiserum raised against A. actinomycetemcomitans serotype d to the competing whole-cell serotype d antigen. The isolated antigen contained LPS, and an equal concentration of LPS isolated from A. actinomycetemcomitans serotype d gave a similar displacement curve in the ELISA. In order to test the immunogenic properties of the isolated antigen, it was used to immunize a rabbit. The antiserum raised against the isolated antigen displayed specificity in Western blotting and ELISA similar to that of antibody raised against LPS isolated from A. actinomycetemcomitans serotype d. In conclusion, our results show that the A. actinomycetemcomitans serotype d-specific antigen contains the O-antigenic structure of LPS.
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| 10. |
- Paino, Annamari, et al.
(författare)
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Trimeric Form of Intracellular ATP Synthase Subunit β of Aggregatibacter actinomycetemcomitans Binds Human Interleukin-1β.
- 2011
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Ingår i: PloS one. - : Public Library of Science. - 1932-6203. ; 6:4, s. e18929-
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Tidskriftsartikel (refereegranskat)abstract
- Bacterial biofilms resist host defenses and antibiotics partly because of their decreased metabolism. Some bacteria use proinflammatory cytokines, such as interleukin (IL)-1β, as cues to promote biofilm formation and to alter virulence. Although one potential bacterial IL-1β receptor has been identified, current knowledge of the bacterial IL-1β sensing mechanism is limited. In chronic biofilm infection, periodontitis, Aggregatibacter actinomycetemcomitans requires tight adherence (tad)-locus to form biofilms, and tissue destroying active lesions contain more IL-1β than inactive ones. The effect of IL-1β on the metabolic activity of A. actinomycetemcomitans biofilm was tested using alamarBlue™. The binding of IL-1β to A. actinomycetemcomitans cells was investigated using transmission electron microscopy and flow cytometry. To identify the proteins which interacted with IL-1β, different protein fractions from A. actinomycetemcomitans were run in native-PAGE and blotted using biotinylated IL-1β and avidin-HRP, and identified using mass spectroscopy. We show that although IL-1β slightly increases the biofilm formation of A. actinomycetemcomitans, it reduces the metabolic activity of the biofilm. A similar reduction was observed with all tad-locus mutants except the secretin mutant, although all tested mutant strains as well as wild type strains bound IL-1β. Our results suggest that IL-1β might be transported into the A. actinomycetemcomitans cells, and the trimeric form of intracellular ATP synthase subunit β interacted with IL-1β, possibly explaining the decreased metabolic activity. Because ATP synthase is highly conserved, it might universally enhance biofilm resistance to host defense by binding IL-1β during inflammation.
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| 11. |
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| 12. |
- Pussinen, PJ, et al.
(författare)
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Antibodies to periodontal pathogens are associated with coronary heart disease.
- 2003
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Ingår i: Arteriosclerosis, thrombosis, and vascular biology. - 1524-4636. ; 23:7, s. 1250-1254
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: We analyzed the association of coronary heart disease (CHD) and serology of periodontitis in a random sample (n=1163) of men (aged 45 to 74 years) by determining serum IgG-antibodies to Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis. METHODS AND RESULTS: CHD (n=159) was more prevalent among edentulous than dentate subjects (19.8% and 12.1%, P=0.003). In the dentate population, CHD was more common among subjects seropositive for P. gingivalis compared with those seronegative (14.0% and 9.7%, P=0.029). Accordingly, CHD was more prevalent in subjects with a high combined antibody response than those with a low response (17.4% and 11.1%, P=0.026). When adjusted for age and several CHD risk factors, the subjects with a high combined antibody response had an odds ratio of 1.5 (95% CI, 0.95 to 2.50, P=0.077) for prevalent CHD. In a linear regression model, the combined antibody response was directly associated with prevalent CHD (P=0.046) and inversely with serum HDL cholesterol concentration (P=0.050). CONCLUSIONS: In conclusion, edentulousness and serum antibodies to major periodontal pathogens were associated with CHD. This suggests that periodontal infection or response of the host against the infection may play a role in the pathogenesis of CHD.
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| 13. |
- Pussinen, PJ, et al.
(författare)
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Periodontitis is associated with a low concentration of vitamin C in plasma.
- 2003
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Ingår i: Clinical and Diagnostic Laboratory Immunology. - 1071-412X. ; 10:5, s. 897-902
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Tidskriftsartikel (refereegranskat)abstract
- This study aimed to clarify how concentrations of vitamin C in plasma relate to the serology of periodontitis. The random sample used comprised 431 men, 194 from Finland and 237 from Russia. The plasma vitamin C concentration was determined by o-phtaldialdehyde-fluorometry, and serum immunoglobulin G antibodies to Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis were determined by a multiserotype enzyme-linked immunosorbent assay (ELISA). The mean plasma vitamin C concentration was higher (P < 0.001) in Finnish subjects (mean +/- standard deviation, 4.5 +/- 2.8 mg/liter) than in Russian subjects (1.4 +/- 1.8 mg/liter). Mean antibody levels to both A. actinomycetemcomitans (4.7 +/- 3.6 versus 5.2 +/- 3.1 ELISA units [P = 0.05]) and P. gingivalis (5.7 +/- 2.5 versus 7.6 +/- 2.9 ELISA units [P < 0.001]) were lower in Finnish men than in Russian men. In the combined Finnish and Russian population, the antibody levels to P. gingivalis were negatively correlated with vitamin C concentrations (r = -0.22; P < 0.001); this association remained statistically significant (P = 0.010) in a linear regression model after adjustment for confounding factors. The proportion of P. gingivalis-seropositive subjects decreased with increasing vitamin C concentrations (P for trend, <0.01), but no trend was seen among A. actinomycetemcomitans-seropositive subjects. In conclusion, P. gingivalis infection is associated with low concentrations of vitamin C in plasma, which may increase colonization of P. gingivalis or disturb the healing of the infected periodontium.
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| 15. |
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