| 1. |
- Alonso-Blanco, Carlos, et al.
(author)
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1,135 Genomes Reveal the Global Pattern of Polymorphism in Arabidopsis thaliana
- 2016
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In: Cell. - : Elsevier. - 0092-8674 .- 1097-4172. ; 166:2, s. 481-491
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Journal article (peer-reviewed)abstract
- Arabidopsis thaliana serves as a model organism for the study of fundamental physiological, cellular, and molecular processes. It has also greatly advanced our understanding of intraspecific genome variation. We present a detailed map of variation in 1,135 high-quality re-sequenced natural inbred lines representing the native Eurasian and North African range and recently colonized North America. We identify relict populations that continue to inhabit ancestral habitats, primarily in the Iberian Peninsula. They have mixed with a lineage that has spread to northern latitudes from an unknown glacial refugium and is now found in a much broader spectrum of habitats. Insights into the history of the species and the fine-scale distribution of genetic diversity provide the basis for full exploitation of A. thaliana natural variation through integration of genomes and epigenomes with molecular and non-molecular phenotypes.
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| 2. |
- Antoniou-Kourounioti, Rea L., et al.
(author)
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Temperature Sensing Is Distributed throughout the Regulatory Network that Controls FLC Epigenetic Silencing in Vernalization
- 2018
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In: Cell systems. - : Elsevier BV. - 2405-4712. ; 7:6, s. 643-655
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Journal article (peer-reviewed)abstract
- Many organisms need to respond to complex, noisy environmental signals for developmental decision making. Here, we dissect how Arabidopsis plants integrate widely fluctuating field temperatures over month-long timescales to progressively upregulate VERNALIZATION INSENSITIVE3 (VIN3) and silence FLOWERING LOCUS C (FLC), aligning flowering with spring. We develop a mathematical model for vernalization that operates on multiple timescales-long term (month), short term (day), and current (hour)-and is constrained by experimental data. Our analysis demonstrates that temperature sensing is not localized to specific nodes within the FLC network. Instead, temperature sensing is broadly distributed, with each thermosensory process responding to specific features of the plants' history of exposure to warm and cold. The model accurately predicts FLC silencing in new field data, allowing us to forecast FLC expression in changing climates. We suggest that distributed thermosensing may be a general property of thermoresponsive regulatory networks in complex natural environments.
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| 3. |
- Axelsson, Susanna, et al.
(author)
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Effect of combined caries-preventive methods: a systematic review of controlled clinical trials.
- 2004
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In: Acta odontologica Scandinavica. - : Informa UK Limited. - 0001-6357 .- 1502-3850. ; 62:3, s. 163-9
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Research review (peer-reviewed)abstract
- The aim of this systematic review was to evaluate the caries-preventive effect of combined caries-preventive methods, defined as two or more different interventions in combination, each expected to prevent dental caries. The Medline database was searched for articles published in the period January 1966 to June 2003. Twenty-four controlled studies met the inclusion criteria, and their value as evidence was assessed according to predetermined criteria. The level of evidence for the overall conclusion regarding each method was graded according to the protocol of the Swedish Council on Technology Assessment in Health Care. The scientific evidence for the combination of treatments involving fluoride that had a preventive effect on caries in children and adolescents was graded as moderate. However, for elderly patients the scientific evidence for the caries-preventive effect of different combinations of treatments was found to be incomplete. No conclusion could be drawn regarding the evidence for combinations of treatments being effective for groups at high caries risk, as the results from the identified clinical studies were conflicting.
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| 4. |
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| 5. |
- Brachi, B., et al.
(author)
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Plant genetic effects on microbial hubs impact host fitness in repeated field trials
- 2022
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In: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 119:30
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Journal article (peer-reviewed)abstract
- Although complex interactions between hosts and microbial associates are increasingly well documented, we still know little about how and why hosts shape microbial communities in nature. In addition, host genetic effects on microbial communities vary widely depending on the environment, obscuring conclusions about which microbes are impacted and which plant functions are important. We characterized the leaf microbiota of 200 Arabidopsis thaliana genotypes in eight field experiments and detected consistent host effects on specific, broadly distributed microbial species (operational taxonomic unit [OTUs]). Host genetic effects disproportionately influenced central ecological hubs, with heritability of particular OTUs declining with their distance from the nearest hub within the microbial network. These host effects could reflect either OTUs preferentially associating with specific genotypes or differential microbial success within them. Host genetics associated with microbial hubs explained over 10% of the variation in lifetime seed production among host genotypes across sites and years. We successfully cultured one of these microbial hubs and demonstrated its growth-promoting effects on plants in sterile conditions. Finally, genome-wide association mapping identified many putatively causal genes with small effects on the relative abundance of microbial hubs across sites and years, and these genes were enriched for those involved in the synthesis of specialized metabolites, auxins, and the immune system. Using untargeted metabolomics, we corroborate the consistent association between variation in specialized metabolites and microbial hubs across field sites. Together, our results reveal that host genetic variation impacts the microbial communities in consistent ways across environments and that these effects contribute to fitness variation among host genotypes.
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| 6. |
- Bång, Åsa, et al.
(author)
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Control of plant species diversity in riparian corridors : Konferens OIKOS 2002
- 2002
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Conference paper (other academic/artistic)abstract
- previous study has shown that plant communities differ floristically between impoundments but remain similar within impoundments in a regulated river. The same pattern did not occur among plant species in a free-flowing river which instead showed a continuous change in species composition from the headwaters to the coast. This strongly suggests that the dispersal of plants is obstructed when dams are built on rivers. The present project will specifically study whether dams also affect the genetic diversity among and between populations of plant species. Filipendula ulmaria will be used as a first test species. A second question is whether tributaries have any impact on the distribution of genetic diversity of plant species within impoundments. A third question deals with the impact of seed and pollen dispersal on the genetic diversity among and between plant species populations. The project combines field sampling, field experiments and laboratory methods such as isoenzymes, microsatellites and other DNA-methods.
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| 7. |
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| 8. |
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| 9. |
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| 10. |
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| 11. |
- Bång, Åsa, et al.
(author)
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The potential role of tributaries as seed sources to an impoundment in northern Sweden : a field experiment with seed mimics
- 2007
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In: Rivers Research and Applications. - : Wiley. - 1535-1459 .- 1535-1467. ; 23:10, s. 1049-1057
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Journal article (peer-reviewed)abstract
- Fragmentation and flow regulation of rivers by large dams are known to obstruct the longitudinal dispersal of waterborne plant propagules between impoundments, and to affect plant community composition. However, even several decades after a dam has been built, impoundments may still have a relatively species-rich riparian flora. We hypothesized that free-flowing tributaries act as the major gene pools for such impoundments, thus alleviating the fragmenting effect large dams have on the main channel. The importance of tributaries as seed sources was tested by releasing wooden seed mimics in three different-sized (0.22-6.93 m3 s-1) tributaries of an impoundment in the Ume River in northern Sweden. In each tributary seed mimics were released, during the spring flood peak, from three points approximately 1, 2 and 3 km upstream the outlet in the impoundment. The importance of a tributary as a seed source increased with tributary size. Of the 9000 released seed mimics 1.5 % reached the impoundment; 1.2 % of the 9000 originated from the largest tributary and 0.3 % from the middle-sized one. The smallest tributary retained all its mimics.
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| 12. |
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| 13. |
- Bång, Åsa, et al.
(author)
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What is the role of tributaries as seed sources for a run-of-river impoundment: a field experiment : Konferens SISORL 2004
- 2004
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Conference paper (other academic/artistic)abstract
- The reservoirs in impounded rivers are blocked by dams, implying that plant seeds, especially waterborne ones, have trouble dispersing between reservoirs. We examined whether the tributaries have an important role in the dispersal of seeds to a specific reservoir. We did this by releasing small, coloured wooden cubes in three tributaries of the Stensele reservoir in northern Sweden, one small, one middle-sized and one large-sized. This work was carried out in spring during major flood. At the day of cube release, we counted the number of cubes that dispersed from the tributaries out into the reservoir. In summer, we collected the cubes that had stranded on the banks of the tributaries to learn how far they had spread within each stream. Our examinations showed that a big stream disperses most seeds the longest distance. The smaller the stream, the shorter the distance the seeds were spread, and the fewer the seeds that reached the reservoir. We concluded that large tributaries have an important role in dispersing plants to reservoirs of impounded rivers.
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| 14. |
- Carlsson, Fredrik, et al.
(author)
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Effect of heat on interspecific competition in saprotrophic wood fungi
- 2014
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In: Fungal ecology. - : Elsevier BV. - 1754-5048 .- 1878-0083. ; 11, s. 100-106
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Journal article (peer-reviewed)abstract
- Some boreal wood fungi that are associated with forest fire or open dry habitats have an increased resistance to heat in comparison to species associated with a less specific distribution or species found in mesic forests. We hypothesize that extreme temperature-stress experienced during fires will favor species adapted to heat and, ultimately, the composition of species inhabiting logs in such habitats will change. Competitiveness after temperature stress was examined in three fire-associated species – Dichomitus squalens, Gloeophyllum sepiarium and Phlebiopsis gigantea – and three non fire-associated species – Ischnoderma benzoinum, Phellinus pini and Fomitopsis pinicola. There was a difference between the fire-associated species and the non fire-associated species with respect to competitive strength after heat stress. All fire-associated species had an advantage after heat treatment, colonizing a larger volume of wood than any non-fire-associated competitor. Our findings suggest that increased heat tolerance of mycelia can exert a competitive balance shift after forest fire. It shows that a system governed by forest fire will be dominance controlled under certain conditions. Furthermore, from a management perspective, during a prescribed burning, certain species already present in the ecosystem will be favored if the fire is not allowed to totally consume the substrates.
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| 15. |
- Carlsson, Fredrik, 1974-, et al.
(author)
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Increased heat resistance in mycelia from wood fungi prevalent in forests characterized by fire : a possible adaptation to forest fire.
- 2012
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In: Fungal Biology. - : Elsevier BV. - 1878-6146 .- 1878-6162. ; 116:10, s. 1025-1031
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Journal article (peer-reviewed)abstract
- AbstractForest fire has for a long time been the major stand replacing/modifying disturbance in boreal forests. For organisms to adopt to this phenomenon different strategies for protective measurements has evolved. This study focuses on the organism group of wood fungi, and one of several possibilities for adaptation to forest fire - increased heat resistance in the mycelia. 16 species of wood fungi where selected and sorted a priori according to their prevalence for fire affected substrate. These were isolated and re-inoculated on pine wood before testing. Experiments where done in a series where the mycelia was exposed to 100, 140, 180, 220°C for 5, 10, 15, 20, 15 min. A very clear difference was found, the group containing species with a prevalence for a fire affected substrate had a much higher survival rate over all combinations of time and temperature compared to species with a more general ecology. This data suggests that increased heat resistance in mycelia could be a possible adaptation to forest fire. This in turn has major impacts on the ecology and population dynamics of wood fungi. An increase in temperature could shift the population structure in a log, allowing minor non fruiting mycelia content to expand on the expense of earlier dominant colonizers. Furthermore this study has implications on how to control prescribed restoration burning events. When burning areas where the dead wood content is dominated by early decay stages, loss of species can be avoided by proper management.
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| 16. |
- Carlsson, Fredrik, 1974-, et al.
(author)
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SNP development for P. gigantea; Method and resources. Primer note
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Other publication (other academic/artistic)abstract
- Phlebiopsis gigantea is an interesting species from many perspectives. It is common in many forests and can often be seen as an early colonizer on fresh wood after a clear cutting. After a forest fire it has been found to be abundant in newly burned forests, in some cases being the dominating species on the majority of logs and stumps (Olsson and Jonsson 2009; Eriksson et al. in prep.). In a study to test heat tolerance in species possibly favored by forest fire P. gigantea showed a remarkable resistance, allowing it not only to survive the forest fire but also to thrive in the microclimatic situation created by the event (Carlsson et al. in press). It is used by forest agencies as a bio controller against Root rot (Rotstop©) from Heterobasidium annosum in parts of boreal fennoscandia, applied at 47 000 ha annually. The practice is that a solution of fungal spores is sprayed on to stumps of already logged trees to prevent the spread of the protagonist fungi. Spores from only one strain of P. gigantea have been used for preparation until the year of 2005 (Rishbeth 1959, Tohr 2003). The spread of genetic material from one individual could have consequences on the population structure of the species as well as other species present in the ecosystem. Stenlid et al. 2009 investigated the population structure in strains from 11 populations spread across the boreal zone from Finland to North America, using microsatellite markers. And found that, so far very little effect from the use of the fungicide was detectable outside of the plots where Rotstop© was applied (Stenlid et al 2009).We aim to develop a set of snp markers for further use in a population study, looking at the effectors mentioned above. We will try to exclude the influence of fungicide usage to detect structures possibly created by forest fire.
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| 17. |
- Carlsson, Fredrik, 1974-, et al.
(author)
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Strong clustering in a SNP study of Phlebiopsis gigantea in sweden
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Other publication (other academic/artistic)abstract
- The population structures of wood decaying basidomycetes depend on several factors; one is dispersal pattern of spores, another is age structure including lifespan and also environmental impacts like forest fires. Phlebiopsis gigantea has been shown to be in the group of basidomycetes that have a well developed tolerance to heat, is long-distance wind dispersed and whose fruit body show up early in succession on fallen logs. In a study of 132 individuals from 3 pairs of locations, 350 km apart, in middle to northern Sweden we used 26 SNP-markers in 6 loci to make a genetic clustering study using STRUCTURE (v. 2.3.4.). The hypothesis; first, clustering should follow the geographic sampling locations with more gene flow between geographically close locations, second; that genetic distance between different clusters should be low due to the long distance dispersal of spores, third; as markers are random we don’t expect to find a correlation between locations affected by forest fires and locations not affected by forest fires. In the study we found 5 clusters (Pr[K= 1]) with moderate to high Fst values (0,0697-03939). Clusters had a poor geographical correlation to sampled populations indicating a complicated population structure. Out of 132 individuals 119 had a private genotype showing a large genetic variation over the total area and a low level of clones in the field.
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| 18. |
- Carlsson, Fredrik, 1974-, et al.
(author)
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Testing the probability of finding major decomposing basidiomycetes in logs with T-RFLP - implications for field sampling
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Other publication (other academic/artistic)abstract
- In this article we examine the limitations and potential of T-RFLP for the accurate detection of fungal species in dead wood. We collected cross-sections of decayed logs to evaluate the number of fungal species domains that are likely to be hit when drilling a sawdust sample from a log. We used these estimates to simulate the number of species that would be found using a certain number of samples. We found that in 99% of the simulations, 4 or fewer species would be contained in a sample. Based on these results we tested the probability of detecting two species of wood-decaying basidiomycetes at three different DNA concentration ratios: 1:1, 1:5 and 1:20. An additional experiment was done with 3-5 species. It was possible to detect all species at ratios higher than 1:20 but lower than 1:5; in this range all peaks were easily detected. We were able to detect all species in the mixtures of 3-5 species, with extracts from both pure cultures and wood.
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| 19. |
- Carlsson, Fredrik, 1974-
(author)
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Wood Fungi and Forest Fire
- 2014
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Doctoral thesis (other academic/artistic)abstract
- Forest fires have been the major stand-replacing/modifying disturbance in boreal forests. To adapt to fire disturbance, different strategies have evolved. This thesis focuses on wood fungi, and the effect of forest fire on this organism group. In many ways it is a study on adaptation to forest fire, in concurrence with adaptation to dry open habitats. In Paper I we study increased heat resistance in mycelia from species prevalent in fire prone environments. Fungi were cultivated on fresh wood and exposed to different temperatures. Species prevalent in fire affected habitats had a much higher survival rate over all combinations of time and temperature compared to species associated with other environments. Based on this results the competitiveness was tested after temperature stress (paper II), three fire associated species, were tested against three non fire associated species. All fire associated species had a clear advantage after heat treatment, conquering a larger volume of wood than its competitor. In paper III we studied the effect of heat shock on decomposition rate, 18 species was tested. Species were cultivated and monitored for CO2 accumulation for 8 weeks and then heat shocked. All species including non fire associated species seemed to up-regulate decomposition after heat shock, this response was more pronounced in fire associated species. To look at the possible effect of forest fire on population structure (Paper IV), we developed 29 SNP/INDELs for Phlebiopsis. gigantea. We amplified the marker containing fragments in 132 individuals of P. gigantea in 6 populations, 3 which were found in areas affected by forest fire and 3 in unaffected areas. We found no genetic structure in accordance to forest fire. However we detected geographic structure, which stands in contrast to earlier studies. This might be due to the method, using SNP´s and number of individuals in the study. Finally we collected cross-sections of decayed logs to evaluate the number of fungal species domains that are likely to be hit when drilling a saw-dust sample in a log. We used these estimates to simulate how many species that will be found by a certain number of samples. We found that in 99% of the
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| 20. |
- Duncan, S., et al.
(author)
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Seasonal shift in timing of vernalization as an adaptation to extreme winter
- 2015
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In: eLIFE. - 2050-084X. ; 4:JULY
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Journal article (peer-reviewed)abstract
- The requirement for vernalization, a need for prolonged cold to trigger flowering, aligns reproductive development with favorable spring conditions. In Arabidopsis thaliana vernalization depends on the cold-induced epigenetic silencing of the floral repressor locus FLC. Extensive natural variation in vernalization response is associated with A. thaliana accessions collected from different geographical regions. Here, we analyse natural variation for vernalization temperature requirement in accessions, including those from the northern limit of the A. thaliana range. Vernalization required temperatures above 0°C and was still relatively effective at 14°C in all the accessions. The different accessions had characteristic vernalization temperature profiles. One Northern Swedish accession showed maximum vernalization at 8°C, both at the level of flowering time and FLC chromatin silencing. Historical temperature records predicted all accessions would vernalize in autumn in N. Sweden, a prediction we validated in field transplantation experiments. The vernalization response of the different accessions was monitored over three intervals in the field and found to match that when the average field temperature was given as a constant condition. The vernalization temperature range of 0–14°C meant all accessions fully vernalized before snowfall in N. Sweden. These findings have important implications for understanding the molecular basis of adaptation and for predicting the consequences of climate change on flowering time.
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| 21. |
- Dupaul, Gabriel, et al.
(author)
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Fiberbanks as substrate and feedstock for biological remediation : A practical analytical method development for organic pollutants analysis
- 2020
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In: Book of Abstracts. - : ABA Publishing. - 9789189081031
-
Conference paper (peer-reviewed)abstract
- Fiberbanksfrom the pulp and paper industry are typically contaminated with a wide range ofchlorinated aromatic and aliphatic toxins such as HCB and other chlorinated benzenes, PCB,HCH, DDT, PCDD, PCDF and Chlorophenols. This poses a formidable challenge for theanalyst to develop appropriate analytical methodology for the monitoring of the progress ofremediation.In preparation to this undertaking, an examination of a practical analytical method using oneextraction method, one clean-up and one analysis method for the aforementioned targetcompounds found in the fibrous sediment. This method was performed using acceleratedsolvent extraction (ASE), a modified silica gel column and GC-FID/ECD. Additionally,an assessment of the levels of organic pollutants was conducted,with the purposeofmeasuringthe potential alteration in contaminantswhenfreeze-drying, air-drying andautoclavingpretreatments are applied to the sediment samples, prior to be used as a media forbiological remediation.The results showed that the ASE is a very fast and reliable method of extraction, with yieldscomparableorhigher than the reference Soxhlet extraction method. Theactivatedsilica gelcolumn demonstrated adequate purification of the sediment extract for analysisusingthe twodetectors, FID and ECD, whichwere able to identify the target analytes fromonlyone purifiedextract. The method employed in this study has the potentialto reduceboth processing timeand materialusedfor analytical sample preparation. Lastly, some modifications inconcentrations anddistribution of target analyteswere revealedin thesediments pre-treated byautoclave and air-driedwhencompared withthefreeze-dried sediments, which can helpunderstanding the development of the biological remediation process.
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| 22. |
- Haller, Henrik, 1977-, et al.
(author)
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Polluted lignocellulose-bearing sediments as a resource for marketable goods—a review of potential technologies for biochemical and thermochemical processing and remediation
- 2023
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In: Clean Technologies and Environmental Policy. - : Springer Science and Business Media LLC. - 1618-954X .- 1618-9558. ; 25, s. 409-425
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Journal article (peer-reviewed)abstract
- Lignocellulose-bearing sediments are legacies of the previously unregulated wastewater discharge from the pulp and paper industry, causing large quantities of toxic organic waste on the Baltic Sea floor and on the bottom of rivers and lakes. Several km2 are covered with deposits of lignocellulosic residues, typically heavily contaminated with complex mixtures of organic and inorganic pollutants, posing a serious threat to human and ecological health. The high toxicity and the large volume of the polluted material are challenges for remediation endeavours. The lignocellulosic material is also a considerable bioresource with a high energy density, and due to its quantity, it could appeal to commercialization as feedstock for various marketable goods. This study sets out to explore the potential of using this polluted material as a resource for industrial production at the same time as it is detoxified. Information about modern production methods for lignocellulosic material that can be adapted to a polluted feedstock is reviewed. Biochemical methods such as composting, anaerobic digestion, as well as, thermochemical methods, for instance, HTC, HTL, pyrolysis, gasification and torrefaction have been assessed. Potential products from lignocellulose-bearing sediment material include biochar, liquid and gaseous biofuels, growing substrate. The use of a contaminated feedstock may make the process more expensive, but the suggested methods should be seen as an alternative to remediation methods that only involve costs. Several experiments were highlighted that support the conception that combined remediation and generation of marketable goods may be an appropriate way to address polluted lignocellulose-bearing sediments. Graphic abstract: [Figure not available: see fulltext.]
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| 23. |
- Haller, Henrik, 1977-, et al.
(author)
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Polluted lignocellulose waste as a resource for marketable products
- 2020
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In: Proceedings Linnaeus ECO-TECH 2020. - 9789189081031
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Conference paper (peer-reviewed)abstract
- Fiberbanks and fiber-rich sediments are legacies of the previously unregulated wastewater discharge from the pulp and paper industry that have accumulated large quantities of toxic organic waste on the Baltic Sea floor and on the bottom of rivers and lakes. Several km2 are covered with deposits of fibrous residues that are, typically, heavily polluted with a number of organic and inorganic substances, posing a serious threat to human and ecological health. High toxicity and the large volume of the polluted material are challenges for remediation endeavors. However, since the fibrous material is a bioresource with a high energy density, the sheer quantity of it could appeal to commercialization as feedstock for various marketable products. This study sets out to explore the potential of using this polluted material as a resource for industrial production, by reviewing and synthesizing data about modern production methods or reuse alternatives for lignocellulose material that can be adapted to a polluted feedstock. Biochemical methods such as composting, anaerobic digestion, as well as, thermochemical methods, for instance, HTC, HTL, pyrolysis, gasification etc. have been assessed. Potential end products from fiber bank material include biochar, liquid and gaseous biofuels, growth media, and fatty acids and proteins produced by white-rot fungi.
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| 24. |
- Hepworth, Jo, et al.
(author)
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Absence of warmth permits epigenetic memory of winter in Arabidopsis
- 2018
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 9:1
-
Journal article (peer-reviewed)abstract
- Plants integrate widely fluctuating temperatures to monitor seasonal progression. Here, we investigate the temperature signals in field conditions that result in vernalisation, the mechanism by which flowering is aligned with spring. We find that multiple, distinct aspects of the temperature profile contribute to vernalisation. In autumn, transient cold temperatures promote transcriptional shutdown of Arabidopsis FLOWERING LOCUS C (FLC), independently of factors conferring epigenetic memory. As winter continues, expression of VERNALIZATION INSENSITIVE3 (VIN3), a factor needed for epigenetic silencing, is upregulated by at least two independent thermosensory processes. One integrates long-term cold temperatures, while the other requires the absence of daily temperatures above 15 °C. The lack of spikes of high temperature, not just prolonged cold, is thus the major driver for vernalisation. Monitoring of peak daily temperature is an effective mechanism to judge seasonal progression, but is likely to have deleterious consequences for vernalisation as the climate becomes more variable.
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| 25. |
- Hepworth, Jo, et al.
(author)
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Natural variation in autumn expression is the major adaptive determinant distinguishing Arabidopsis FLC haplotypes
- 2020
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In: eLIFE. - 2050-084X. ; 9
-
Journal article (peer-reviewed)abstract
- In Arabidopsis thaliana, winter is registered during vernalization through the temperature-dependent repression and epigenetic silencing of floral repressor FLOWERING LOCUS C (FLC). Natural Arabidopsis accessions show considerable variation in vernalization. However, which aspect of the FLC repression mechanism is most important for adaptation to different environments is unclear. By analysing FLC dynamics in natural variants and mutants throughout winter in three field sites, we find that autumnal FLC expression, rather than epigenetic silencing, is the major variable conferred by the distinct Arabidopsis FLChaplotypes. This variation influences flowering responses of Arabidopsis accessions resulting in an interplay between promotion and delay of flowering in different climates to balance survival and, through a post-vernalization effect, reproductive output. These data reveal how expression variation through non-coding cis variation at FLC has enabled Arabidopsis accessions to adapt to different climatic conditions and year-on-year fluctuations.
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| 26. |
- Hepworth, Jo, et al.
(author)
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Natural variation in autumn expression is the major adaptive determinant distinguishing arabidopsis flc haplotypes
- 2020
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In: eLife. - 2050-084X. ; 9
-
Journal article (peer-reviewed)abstract
- In Arabidopsis thaliana, winter is registered during vernalization through the temperature-dependent repression and epigenetic silencing of floral repressor FLOWERING LOCUS C (FLC). Natural Arabidopsis accessions show considerable variation in vernalization. However, which aspect of the FLC repression mechanism is most important for adaptation to different environments is unclear. By analysing FLC dynamics in natural variants and mutants throughout winter in three field sites, we find that autumnal FLC expression, rather than epigenetic silencing, is the major variable conferred by the distinct Arabidopsis FLChaplotypes. This variation influences flowering responses of Arabidopsis accessions resulting in an interplay between promotion and delay of flowering in different climates to balance survival and, through a post-vernalization effect, reproductive output. These data reveal how expression variation through non-coding cis variation at FLC has enabled Arabidopsis accessions to adapt to different climatic conditions and year-on-year fluctuations.
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| 27. |
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| 28. |
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| 29. |
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| 30. |
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| 31. |
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| 32. |
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| 33. |
- Högberg, Björn, et al.
(author)
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Study of DNA-Coated Nanoparticles as Possible Programmable Self-Assembly Building-Blocks
- 2006
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In: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 252:15, s. 5538-5541
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Journal article (peer-reviewed)abstract
- Nanoparticles coated with single stranded DNA have been shown to efficiently hybridize to targets of complementary DNA. This property might be used to implement programmable (or algorithmic) self-assembly to build nanoparticle structures. However, we argue that a DNA coated nanoparticle by itself cannot be used as a programmable self-assembly building block since it does not have directed bonds. A general scheme for assembling and purifying nanoparticle eight-mers with eight geometrically well-directed bonds is presented together with some preliminary experimental work.
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| 34. |
- Kawakatsu, Taiji, et al.
(author)
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Epigenomic Diversity in a Global Collection of Arabidopsis thaliana Accessions
- 2016
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In: Cell. - : Elsevier. - 0092-8674 .- 1097-4172. ; 166:2, s. 492-505
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Journal article (peer-reviewed)abstract
- The epigenome orchestrates genome accessibility, functionality, and three-dimensional structure. Because epigenetic variation can impact transcription and thus phenotypes, it may contribute to adaptation. Here, we report 1,107 high-quality single-base resolution methylomes and 1,203 transcriptomes from the 1001 Genomes collection of Arabidopsis thaliana. Although the genetic basis of methylation variation is highly complex, geographic origin is a major predictor of genome-wide DNA methylation levels and of altered gene expression caused by epialleles. Comparison to cistrome and epicistrome datasets identifies associations between transcription factor binding sites, methylation, nucleotide variation, and co-expression modules. Physical maps for nine of the most diverse genomes reveal how transposons and other structural variants shape the epigenome, with dramatic effects on immunity genes. The 1001 Epigenomes Project provides a comprehensive resource for understanding how variation in DNA methylation contributes to molecular and non-molecular phenotypes in natural populations of the most studied model plant.
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| 35. |
- Krintel, Christian, et al.
(author)
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Ser649 and Ser650 are the major determinants of protein kinase A-mediated activation of human hormone-sensitive lipase against lipid substrates.
- 2008
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In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 3:11
-
Journal article (peer-reviewed)abstract
- BACKGROUND: Hormone-sensitive lipase (HSL) is a key enzyme in the mobilization of fatty acids from stored triacylglycerols. Its activity is regulated by reversible protein phosphorylation. In rat HSL Ser563, Ser659 and Ser660 have been shown to be phosphorylated by protein kinase A (PKA) in vitro as well as in vivo. METHODOLOGY/PRINCIPAL FINDINGS: In this study we employed site-directed mutagenesis, in vitro phosphorylation and mass spectrometry to show that in vitro phosphorylation of human HSL by PKA occurs primarily on Ser649 and Ser650 (Ser659 and Ser660 in rat HSL). The wild type enzyme and four mutants were expressed in C-terminally His-tagged form in Sf9 insect cells and purified to homogeneity. HSL variants in which Ser552 and/or Ser554 were mutated to Ala or Glu retained both lipolytic and non-lipolytic activity and were phosphorylated by PKA and activated to a similar extent as the wild type enzyme. (32)P-labeling studies revealed that the bulk of the phosphorylation was on the Ser649/Ser650 site, with only a minor phosphorylation of Ser552 and Ser554. MS/MS analysis demonstrated that the peptide containing Ser649 and Ser650 was primarily phosphorylated on Ser650. The mutant lacking all four serines had severely reduced lipolytic activity, but a lesser reduction in non-lipolytic activity, had S(0.5) values for p-nitrophenol butyrate and triolein comparable to those of wild type HSL and was not phosphorylated by PKA. PKA phosphorylation of the wild type enzyme resulted in an increase in both the maximum turnover and S(0,5) using the TO substrate. CONCLUSIONS: Our results demonstrate that PKA activates human HSL against lipid substrates in vitro primarily through phosphorylation of Ser649 and Ser650. In addition the results suggest that Ser649 and Ser650 are located in the vicinity of a lipid binding region and that PKA phosphorylation controls the accessibility of this region.
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| 36. |
- Källestål, Carina, et al.
(author)
-
Economic evaluation of dental caries prevention : a systematic review
- 2003
-
In: Acta Odontologica Scandinavica. - : Informa UK Limited. - 0001-6357 .- 1502-3850. ; 61:6, s. 341-346
-
Research review (other academic/artistic)abstract
- The aim of the present study was to perform a systematic review of economic evaluations of caries prevention. A search in Medline from 1966 until May 2003 and a manual search in a number of journals identified 154 references, 74 of which were included. There were 17 original studies including an economic evaluation, and these form the basis of the present article. The rest were reviews, model studies and reports concerning economic practice in dentistry. The results show that the reviewed original studies on economic evaluation of caries prevention do not provide support for the economic value of caries prevention. The scarcity of well-conducted studies, as well as contra-dictory evidence in the reviewed articles, makes it difficult to judge the health-economic effect of the studied caries-prevention methods.
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| 37. |
- Larsson, Sara, et al.
(author)
-
Characterization of the Lipid Droplet Proteome of a Clonal Insulin-producing β-Cell Line (INS-1 832/13).
- 2012
-
In: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 11:2, s. 1264-1273
-
Journal article (peer-reviewed)abstract
- Lipids are known to play a crucial role both in the normal control of insulin release and in the deterioration of β-cell function, as observed in type 2 diabetes. Despite this established dual role of lipids, little is known about lipid storage and handling in β-cells. Here, we isolated lipid droplets from oleate-incubated INS-1 832/13 cells and characterized the lipid droplet proteome. In a total of four rounds of droplet isolation and proteomic analysis by HPLC-MS/MS, we identified 96 proteins that were specific to droplets. The proteins fall into six categories based on function or previously observed localization: metabolism, endoplasmic reticulum/ribosomes, mitochondria, vesicle formation and transport, signaling, and miscellaneous. The protein profile reinforces the emerging picture of the lipid droplet as an active and dynamic organelle involved in lipid homeostasis and intracellular trafficking. Proteins belonging to the category mitochondria were highly represented, suggesting that the β-cell mitochondria and lipid droplets form a metabolic unit of potential relevance for insulin secretion.
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| 38. |
- Lingström, Peter, et al.
(author)
-
Dietary factors in the prevention of dental caries : a systematic review
- 2003
-
In: Acta Odontologica Scandinavica. - : Informa Healthcare. - 0001-6357 .- 1502-3850. ; 61:6, s. 331-340
-
Research review (other academic/artistic)abstract
- The aim of this study was, systematically, to evaluate the effect of die-tary changes in the prevention of dental caries. A search and analysis strategy was followed, as suggested by the Swedish Council on Tech-nology Assessment in Health Care (SBU). The search strategy for arti-cles published in 1966-2003 was performed using electronic databases and reference lists of articles and selected textbooks. Out of 714 arti-cles originally identified, 18 met the inclusion criteria for a random-ized or controlled clinical trial--at least 2 years’ follow-up and caries increment as a primary endpoint. This included the total or partial substitution of sucrose with sugar substitutes or the addition of pro-tective foods to chewing gum. No study was found evaluating the ef-fect of information designed to reduce sugar intake/frequency as a sin-gle preventive measure. It is suggested that the evidence for the use of sorbitol or xylitol in chewing gum, or for the use of invert sugar, is in-conclusive. No caries-preventive effect was found from adding calcium phosphate or dicalcium phosphate dihydrate to chewing gums. The review clearly demonstrates the need for well-designed randomized clinical studies with adequate control groups and high compliance.
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| 39. |
- Lingärde, Svante, et al.
(author)
-
Om barnfattigdom - ansvar, insatser och orsaker
- 2006
-
Book (other academic/artistic)abstract
- Denna rapport syftar till att ge en flervetenskaplig belysning av olika aspekter av barnfattigdom i dagens Sverige och i Stockholm. Perspektiven är historiska, juridiska, politiska, ekonomiska och sociala. I en historisk jämförelse framträder bl a att barnen under det senaste halvseklet kommit att bli allt mera överrepresenterade bland dem som får ekonomiskt bistånd i Sverige. De juridiska aspekterna av samhällets ansvar problematiseras i relation till tolkningen av FN:s Barnkonvention. Uppgiftsfördelningen mellan överstatliga och mellanstatliga organ, svenska staten och de svenska kommunerna är emellertid oklar på flera punkter. Detta bidrar till att det kan bli svårt att uppfylla EU:s mål att utrota barnfattigdomen till 2010. Ett stort ansvar ligger på kommunerna, som emellertid har små möjligheter att strategiskt påverka barnfattigdomen. En närmare studie av Stockholms stad visar bl a på en fortgående process av segregation mellan stadsdelarna. Samtidigt som barnperspektivet blivit tydligare i de kommunala verksamheterna de senaste åren, kvarstår stora svårigheter att agera långsiktigt inom dessa verksamheter. Avslutningsvis diskuteras ämnesövergripande och ideologiska aspekter av arbetet mot barnfattigdom.
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| 40. |
- Lingärde, Svante, et al.
(author)
-
Vägen tillbaka - om socialtjänsten, Försäkringskassan och de långtidssjukskrivna
- 2007
-
Book (other academic/artistic)abstract
- Socialtjänstens arbete med arbetslivsinriktad rehabilitering är omfattande och har på senare år kommit att få en växande betydelse genom att allt fler långtidssjuka står utan både arbete och socialförsäkringsskydd. I denna rapport undersöks hur socialtjänsten i Stockholm arbetar med långtidssjuka personer som är nollklassade hos Försäkringskassan. En forskningsöversikt görs om orsakerna till de höga sjuktalen i Sverige och vilka faktorer som kan påverka långtidssjukas möjligheter att komma tillbaka till arbetslivet. Vidare diskuteras Försäkringskassans, Arbetsmarknadsverkets, arbetsgivarnas och landstingens rehabiliteringsansvar. Därefter studeras, främst genom chefsintervjuer, hur arbetslivsinriktad rehabilitering organiseras inom socialtjänsten i Stockholms stad och fem av stadsdelsförvaltningarna. Avslutningsvis diskuteras vilka konsekvenser den samhälleliga arbetslinjen och organisationen av rehabilitering kan ha för långtidssjuka människor idag.
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| 41. |
- Mejàre, Ingegerd, et al.
(author)
-
Caries-preventive effect of fissure sealants : a systematic review
- 2003
-
In: Acta Odontologica Scandinavica. - : Informa UK Limited. - 0001-6357 .- 1502-3850. ; 61:6, s. 321-330
-
Research review (other academic/artistic)abstract
- The objectives of this study were to evaluate systematically the evi-dence of the caries-preventive effect of fissure sealing of occlusal tooth surfaces and to examine factors potentially modifying the effect. The search strategies included electronic databases, reference lists of arti-cles, and selected textbooks. Inclusion criteria were randomized or quasi-randomized clinical trials or controlled clinical trials comparing fissure sealing with no treatment or another preventive treatment in children up to 14 years of age at the start; the outcome measure was caries increment; the diagnostic criteria had been described; and the follow-up time was at least 2 years. Inclusion decisions were taken and grading of the studies was done independently by two of the authors. The main measure of effect was relative risk reduction. Thirteen stud-ies using resin-based or glass ionomer sealant materials were included in the final analysis. The results showed that most studies were per-formed during the 1970s and a single application had been utilized. The relative caries risk reduction pooled estimate of resin-based seal-ants on permanent 1st molars was 33% (relative risk = 0.67; CI = 0.55-0.83). The effect depended on retention of the sealant. In conclu-sion, the review suggests limited evidence that fissure sealing of 1st permanent molars with resin-based materials has a caries-preventive effect. The evidence is incomplete for permanent 2nd molars, premo-lars and primary molars and for glass ionomer cements. Overall, there remains a need for further trials of high quality, particularly in child populations with a low and a high caries risk, respectively.
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| 42. |
- Nilsson, Christer, et al.
(author)
-
Control of plant species diversity in riparian corridors : Konferens ESEB 2003
- 2003
-
Conference paper (other academic/artistic)abstract
- previous study has shown that plant communities differ floristically between impoundments but remain similar within impoundments in a regulated river. The same pattern did not occur among plant species in a free-flowing river which instead showed a continuous change in species composition from the headwaters to the coast. This strongly suggests that the dispersal of plants is obstructed when dams are built on rivers. The present project will specifically study whether dams also affect the genetic diversity among and between populations of plant species. Filipendula ulmaria will be used as a first test species. A second question is whether tributaries have any impact on the distribution of genetic diversity of plant species within impoundments. A third question deals with the impact of seed and pollen dispersal on the genetic diversity among and between plant species populations. The project combines field sampling, field experiments and laboratory methods such as isoenzymes, microsatellites and other DNA-methods.
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| 43. |
- Novikova, Polina Yu, et al.
(author)
-
Genome Sequencing Reveals the Origin of the Allotetraploid Arabidopsis suecica
- 2017
-
In: Molecular biology and evolution. - : Oxford University Press (OUP). - 0737-4038 .- 1537-1719. ; 34:4, s. 957-968
-
Journal article (peer-reviewed)abstract
- Polyploidy is an example of instantaneous speciation when it involves the formation of a new cytotype that is incompatible with the parental species. Because new polyploid individuals are likely to be rare, establishment of a new species is unlikely unless polyploids are able to reproduce through self-fertilization (selfing), or asexually. Conversely, selfing (or asexuality) makes it possible for polyploid species to originate from a single individual-a bona fide speciation event. The extent to which this happens is not known. Here, we consider the origin of Arabidopsis suecica, a selfing allopolyploid between Arabidopsis thaliana and Arabidopsis arenosa, which has hitherto been considered to be an example of a unique origin. Based on whole-genome re-sequencing of 15 natural A. suecica accessions, we identify ubiquitous shared polymorphism with the parental species, and hence conclusively reject a unique origin in favor of multiple founding individuals. We further estimate that the species originated after the last glacial maximum in Eastern Europe or central Eurasia (rather than Sweden, as the name might suggest). Finally, annotation of the self-incompatibility loci in A. suecica revealed that both loci carry non-functional alleles. The locus inherited from the selfing A. thaliana is fixed for an ancestral non-functional allele, whereas the locus inherited from the outcrossing A. arenosa is fixed for a novel loss-offunction allele. Furthermore, the allele inherited from A. thaliana is predicted to transcriptionally silence the allele inherited from A. arenosa, suggesting that loss of self-incompatibility may have been instantaneous.
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| 44. |
- Novikova, P. Y., et al.
(author)
-
Sequencing of the genus Arabidopsis identifies a complex history of nonbifurcating speciation and abundant trans-specific polymorphism
- 2016
-
In: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 48:9, s. 1077-1082
-
Journal article (peer-reviewed)abstract
- The notion of species as reproductively isolated units related through a bifurcating tree implies that gene trees should generally agree with the species tree and that sister taxa should not share polymorphisms unless they diverged recently and should be equally closely related to outgroups. It is now possible to evaluate this model systematically. We sequenced multiple individuals from 27 described taxa representing the entire Arabidopsis genus. Cluster analysis identified seven groups, corresponding to described species that capture the structure of the genus. However, at the level of gene trees, only the separation of Arabidopsis thaliana from the remaining species was universally supported, and, overall, the amount of shared polymorphism demonstrated that reproductive isolation was considerably more recent than the estimated divergence times. We uncovered multiple cases of past gene flow that contradict a bifurcating species tree. Finally, we showed that the pattern of divergence differs between gene ontologies, suggesting a role for selection. © 2016 Nature America, Inc. All rights reserved.
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| 45. |
- Petersson, Lars G, et al.
(author)
-
Professional fluoride varnish treatment for caries control: a systematic review of clinical trials.
- 2004
-
In: Acta odontologica Scandinavica. - : Informa UK Limited. - 0001-6357 .- 1502-3850. ; 62:3, s. 170-6
-
Research review (peer-reviewed)abstract
- The aim of this paper was systematically to evaluate the caries-preventive effect of professional fluoride varnish treatments. A search of the literature for articles published between 1966 and August 2003 was carried out in electronic databases, reference lists of articles, and selected textbooks in accordance with the strategy of the Swedish Council on Technology Assessment in Health Care. Out of 302 identified papers, 24 randomized and controlled clinical trials comparing fluoride varnish with placebo, no active treatment or other fluoride preventive regimens of at least 2 years' study duration were included. The trials that met the inclusion criteria were assessed independently and systematically by at least two reviewers and scored from A to C according to predetermined criteria for methodology and performance. The main outcome measure was the preventive fraction expressed as a percentage. The results displayed limited evidence (evidence level 3) for the caries preventive effect of topical applications of fluoride varnishes in permanent teeth. The average prevented fraction was 30% (0-69%) when compared with untreated controls. Inconclusive evidence (evidence level 4) was found for fluoride varnish treatment in the primary dentition and in adults. This systematic review reinforces the need for future dinical research of high quality, incorporating modern concepts of dinical performance and evaluation to assess dental caries control using professional fluoride varnish.
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| 46. |
- Plötner, Björn, et al.
(author)
-
Chlorosis caused by two recessively interacting genes reveals a role of RNA helicase in hybrid breakdown in Arabidopsis thaliana
- 2017
-
In: The Plant Journal. - : Wiley. - 0960-7412 .- 1365-313X. ; 91:2, s. 251-262
-
Journal article (peer-reviewed)abstract
- Hybrids often differ in fitness from their parents. They may be superior, translating into hybrid vigour or heterosis, but they may also be markedly inferior, because of hybrid weakness or incompatibility. The underlying genetic causes for the latter can often be traced back to genes that evolve rapidly because of sexual or host-pathogen conflicts. Hybrid weakness may manifest itself only in later generations, in a phenomenon called hybrid breakdown. We have characterized a case of hybrid breakdown among two Arabidopsis thaliana accessions, Shahdara (Sha, Tajikistan) and Lövvik-5 (Lov-5, Northern Sweden). In addition to chlorosis, a fraction of the F2 plants have defects in leaf and embryo development, and reduced photosynthetic efficiency. Hybrid chlorosis is due to two major-effect loci, of which one, originating from Lov-5, appears to encode an RNA helicase (AtRH18). To examine the role of the chlorosis allele in the Lövvik area, in addition to eight accessions collected in 2009, we collected another 240 accessions from 15 collections sites, including Lövvik, from Northern Sweden in 2015. Genotyping revealed that Lövvik collection site is separated from the rest. Crosses between 109 accessions from this area and Sha revealed 85 cases of hybrid chlorosis, indicating that the chlorosis-causing allele is common in this area. These results suggest that hybrid breakdown alleles not only occur at rapidly evolving loci, but also at genes that code for conserved processes.
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| 47. |
- Rauhut, Daniel, et al.
(author)
-
Om barnfattigdom - ansvar, insatser och orsaker
- 2006
-
Book (other academic/artistic)abstract
- Fattigdom, ekonomisk utsatthet och social utestängning bland barn har hittills studerats i begränsad utsträckning inom svensk forskning. Denna rapport syftar till att ge en flervetenskaplig belysning av olika aspekter av barnfattigdom i dagens Sverige och Stockholm. Perspektiven är historiska, juridiska, politiska, ekonomiska och sociala. I en historisk jämförelse framträder det bl. a. att barnen under det senaste halvseklet kommit att bli allt mera överrepresenterade bland dem som får ekonomiskt bistånd i Sverige. Vidare har biståndsnormerna för barn utvecklats mycket ojämnt i förhållande till motsvarande normer för vuxna. De juridiska aspekterna av samhällets ansvar i förhållande till barns utsatthet kan relateras till tolkningen av berörda artiklar som återges i FN:s konvention om barnets rättigheter (Barnkonventionen). Barnets rättigheter ska framförallt ses i ljuset av konventionens vägledande princip om barnets bästa som ska genomsyra all svensk lagstiftning som rör barn. Uppgiftsfördelningen mellan EU, svenska staten och de svenska kommunerna är emellertid oklar på flera punkter. Detta bidrar till att det kan bli svårt att uppfylla EU:s mål att utrota barnfattigdomen till 2010. En kommun har mycket begränsade möjligheter att påverka strategiska faktorer såsom föräldrars position på arbetsmarknaden och i socialförsäkringssystemet. En närmare studie av Stockholms stad visar bl. a. på en fortgående process av segregation mellan stadsdelsområdena. I Stockholms kommunala verksamheter har barnperspektivet blivit tydligare de senaste åren. Samtidigt kvarstår svårigheter att agera långsiktigt från kommunens sida. Avslutningsvis diskuteras övergripande och ideologiska aspekter av arbetet mot barnfattigdom.
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| 48. |
- Rydberg Sterner, Therese, et al.
(author)
-
The Gothenburg H70 Birth cohort study 2014-16: design, methods and study population.
- 2019
-
In: European journal of epidemiology. - : Springer Science and Business Media LLC. - 1573-7284 .- 0393-2990. ; 34:2, s. 191-209
-
Journal article (peer-reviewed)abstract
- To improve health care for older persons, we need to learn more about ageing, e.g. identify protective factors and early markers for diseases. The Gothenburg H70 Birth Cohort Studies (the H70 studies) are multidisciplinary epidemiological studies examining representative birth cohorts of older populations in Gothenburg, Sweden. So far, six birth cohorts of 70-year-olds have been examined over time, and examinations have been virtually identical between studies. This paper describes the study procedures for the baseline examination of the Birth cohort 1944, conducted in 2014-16. In this study, all men and women born 1944 on specific dates, and registered as residents in Gothenburg, were eligible for participation (n=1839). A total of 1203 (response rate 72.2%; 559 men and 644 women; mean age 70.5years) agreed to participate in the study. The study comprised sampling of blood and cerebrospinal fluid, psychiatric, cognitive, and physical health examinations, examinations of genetics and family history, use of medications, social factors, functional ability and disability, physical fitness and activity, body composition, lung function, audiological and ophthalmological examinations, diet, brain imaging, as well as a close informant interview, and qualitative studies. As in previous examinations, data collection serves as a basis for future longitudinal follow-up examinations. The research gained from the H70 studies has clinical relevance in relation to prevention, early diagnosis, clinical course, experience of illness, understanding pathogenesis and prognosis. Results will increase our understanding of ageing and inform service development, which may lead to enhanced quality of care for older persons.
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| 49. |
- Twetman, Svante, et al.
(author)
-
Caries-preventive effect of fluoride toothpaste : a systematic review
- 2003
-
In: Acta Odontologica Scandinavica. - : Informa UK Limited. - 0001-6357 .- 1502-3850. ; 61:6, s. 347-355
-
Research review (other academic/artistic)abstract
- With a questionnaire addressed to general dental practitioners in Sweden, the Swedish Council on Technology Assessment in Health Care launched a project group in 1999 to systematically review and evaluate the existing literature on various caries preventive methods. The aim of this article was to report findings concerning the caries preventive effect of fluoride toothpastes in various age groups, with special emphasis on fluoride concentration and supervised versus non-supervised brushing. A systematic search in electronic databases for articles published between 1966 and April 2003 was conducted with the inclusion criteria of a randomized or controlled clinical trial, at least 2 years follow-up and caries increment in the permanent (DMFS/T) or primary (dmfs/t) dentition as endpoint. Out of 905 articles originally identified, 54 met the inclusion criteria. These studies were assessed independently by at least two reviewers and scored A-C according to predetermined criteria for methodology and performance. The measure of effect was the prevented fraction (PF), expressed as percent. The results revealed strong evidence (level 1) (i) for the caries preventive effect of daily use of fluoride toothpaste compared to placebo in the young permanent dentition (PF 24.9%), (ii) that toothpastes with 1,500 ppm of fluoride had a superior preventive effect compared with standard dentifrices with 1,000 ppm F in the young permanent dentition (PF 9.7%), and (iii) that higher caries reductions were recorded in studies with supervised toothbrushing compared with non-supervised (PF 23.3%). However, incomplete evidence (level 4) was found regarding the effect of fluoride toothpaste in the primary dentition. In conclusion, this review reinforced the importance of daily toothbrushing with fluoridated toothpastes for preventing dental caries, although long-term studies in age groups other than children and adolescents are still lacking.
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| 50. |
- Twetman, Svante, et al.
(author)
-
Caries-preventive effect of sodium fluoride mouthrinses: a systematic review of controlled clinical trials.
- 2004
-
In: Acta odontologica Scandinavica. - Oslo : Informa UK Limited. - 0001-6357 .- 1502-3850. ; 62:4, s. 223-30
-
Research review (peer-reviewed)abstract
- The Swedish Council on Technology Assessment in Health Care launched a project group in 1999 to systematically review and evaluate the existing literature on different caries-preventive methods. The aim of this article was to report the findings concerning the caries-preventive effect of fluoride mouthrinses (FMRs) in various age groups, with special reference to background fluorides. A systematic search in electronic databases for literature published between 1966 and August 2003 was conducted with the inclusion criteria of a randomized or controlled clinical trial, at least 2 years' follow-up, and caries increment in the permanent dentition (DeltaDMFS/T) as endpoint. Out of 174 articles originally identified, 62 met the inclusion criteria. These studies were assessed independently by at least two reviewers and scored A-C according to predetermined criteria for methodology and performance. The measure of effect was the prevented fraction (PF) expressed as percent. The level of evidence was based on 25 articles. The results revealed limited evidence (evidence level 3) for the caries-preventive effect (PF 29%) of daily or weekly sodium fluoride rinses compared with placebo in permanent teeth of schoolchildren and adolescents with no additional fluoride exposure and for a caries-preventive effect on root caries in older adults. Inconclusive evidence (evidence level 4) was found regarding the effect of FMRs in schoolchildren and adolescents exposed to additional fluoride sources such as daily use of fluoride toothpaste. No firm support for the use of FMRs was disclosed in a small number of studies designed for patients at caries risk. Furthermore, no association between the frequency of the rinses and prevented fraction or saved surfaces per year was found. In conclusion, this systematic review suggests that sodium fluoride mouthrinses may have an anti-caries effect in children with limited background of fluoride exposure, while its additional effect in children with daily use of fluoride toothpaste could be questioned. The need for further clinical trials to elucidate the effect of FMRs in risk patients and older adults is emphasized.
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